   NOTE: a more readable HTML version of this INSTALL document can be found
   in courier/doc/install.html.

                                  Installation

   ---------------------------------------------------------------------------

     NOTE:

     This documentation describes manual installation of the Courier server.
     This is a somewhat involved process that may overwhelm people that do
     not have prior experience with installing large software packages. Many
     Linux-based distributions and BSD-family systems have
     separately-maintained, preconfigured, ready-to-install packages that can
     be loaded with much less investment of time. Installing a pre-built
     package would probably be the best approach in this case.

     Should you choose to install a platform-specific prebuilt package, you
     should carefully read any custom documentation files that are included
     in the package. Most platform-specific packages provide custom,
     non-default configuration settings that are optimized for that platform
     unique needs and requirements. Feedback about platform-specific
     precompiled packages should be copied to the development group that
     maintains the package, in additional to the platform-neutral
     courier-users mailing list. They will appreciate the feedback, and take
     it into consideration when preparing the next revision of the
     platform-specific package.

   ---------------------------------------------------------------------------

   Read this document in its entirety before entering a single command.
   Installing Courier for the first time will take a while. If possible,
   consider looking around for anyone who has already packaged Courier for
   your operating system, and save yourself the hassle.

   Fortunately, it gets easier with each subsequent installation. Courier is
   a complicated piece of software. Most problems people will have are likely
   to be with the configuring and installing it correctly. Designing complex
   software that compiles and installs on a wide variety of POSIX systems is
   not a trivial task.

   Courier's configuration and installation scripts are very flexible in
   setting up installation directories for each logical set of files -
   configuration files, binaries, scripts, the mail queue, and more. If you
   begin by installing someone else's package, instead of installing
   everything yourself, you should take careful notes where things are
   installed. If you later decide to roll your own package, you will either
   need to use a COMPLETELY IDENTICAL configuration, or take care to back up
   your old configuration, and then restore it after the upgrade. The
   following documentation refers to the default location of various
   configuration files (and other files as well). If you choose to install
   some files in a non-default location (either by yourself, or by using
   someone else's package), you will need to take this into account while
   reading the following documentation.

   This cannot be emphasized enough: the configuration defaults are very
   generic; the goal is to have the default configuration settings work for
   almost everyone. In every case using at least a couple of non-default
   parameters will make Courier work better on your system. You should
   anticipate going through several trial-and-error installs, tweaking the
   options to see what works better for you. Even my own pre-configured RPM
   package uses a number of non-default parameters.

   NOTE: older versions of the linuxconf configuration tool are hardwired for
   sendmail. They like to change the permission of the sendmail wrapper to
   match the permissions they think the real sendmail should have. Older
   versions of linuxconf also have a tendency to create the /var/spool/mqueue
   directory, even if sendmail is not installed.

Table Of Contents

   The following table of contents might look intimidating at first, but some
   sections are marked "optional". These sections are not required for a
   basic installation as a simple ESMTP server.

     * Upgrading an existing installation
     * Overview
     * Preparing for installation
     * OPTIONAL: Install the Socks 5 client toolkit
     * Run configure
     * IPv6
     * Compile and run make check
     * Installation
     * Install configuration files
     * Adjust system paranoia level
     * Post-installation setup
     * Post-installation checks
     * OPTIONAL: Configure webadmin
     * Create system aliases
     * Create smtp access list
     * Backscatter suppression
     * Miscellaneous configuration
     * Define local domains
     * OPTIONAL: Configure UUCP
     * OPTIONAL: Configure LDAP aliasing
     * OPTIONAL: Configure filtering
     * Create a list of domains to accept mail for
     * Starting and stopping Courier
     * Run Courier in parallel to your mail server
     * OPTIONAL: Configure ESMTP authentication and SSL
     * OPTIONAL: Configure the SECURITY ESMTP extension
     * OPTIONAL: Configure the Sender Policy Framework
     * OPTIONAL: Configure the IMAP server
     * OPTIONAL: Configure IMAP shared folders
     * OPTIONAL: Configure IMAP over SSL
     * OPTIONAL: Sending mail via an IMAP connection
     * OPTIONAL: Configure IMAP realtime folder status updates
     * OPTIONAL: Configure SMAP
     * OPTIONAL: Configure the POP3 server
     * OPTIONAL: Configure POP3 over SSL
     * OPTIONAL: Configure the IMAP/POP3 aggregator proxy
     * OPTIONAL: Configure the webmail server
     * OPTIONAL: Configure webmail calendaring
     * OPTIONAL: Configure mail filtering for the webmail server
     * OPTIONAL: Changing mail account passwords using the webmail server
     * OPTIONAL: Configure autoreplies for the webmail server
     * OPTIONAL: Configure encryption for the webmail server
     * OPTIONAL: Quota support
     * OPTIONAL: Account OPTIONS
     * OPTIONAL: Configure outbound faxing
     * OPTIONAL: Configure inbound faxing
     * OPTIONAL: Install the Courier log analyzer
     * Decommission your existing mail server
     * Sample init script

Upgrading an existing installation

  Upgrading from Courier 0.51, or earlier.

   Version 2.0 of maildrop, in Courier 0.52, introduces a new pattern
   matching engine that uses the PCRE library, that uses a completely
   different syntax. However, very few changes should be required to upgrade
   existing maildrop recipes to the new syntax.

   After upgrading from Courier 0.51, or earlier, review the maildropfilter
   manual page which has been revised to document the new pattern matching
   syntax. The legacy pattern matching engine is still available by setting
   MAILDROP_OLD_REGEXP to 1. See also the "Conversion of maildrop 1.x pattern
   to 2.0" section in the manual page, for more information.

  Upgrading from Courier 0.49.0, or earlier.

   couriermlm's default configuration now treats both the userid and the
   domain portion of E-mail addresses as case-insensitive.

   Any existing mailing list that has subscribers whose E-mail addresses
   contain uppercase addresses must explicitly set the new CASESENSITIVE=1
   list option, using the couriermlm command, otherwise those subscribers
   will have problems unsubscribing or posting messages to the list.

  Upgrading from Courier 0.48.2, or earlier.

   Courier's default configuration now includes backscatter suppression.
   Review Backscatter suppression, below, for any needed configuration
   changes.

  Upgrading from Courier 0.47, or earlier.

   Beginning with 0.48, the authentication library that used to be a part of
   Courier's source has been spun off into a standalone authentication
   library.

   You must download and install the Courier authentication library from
   http://www.courier-mta.org/authlib/ before upgrading. Review the
   documentation in the courier-authlib package for more information.

   As part of installing courier-authlib, the configuration files in
   Courier's configuration directory that relate to authentication will be
   copied to courier-authlib's configuration directory. The files are:
   authdaemonrc, authmysqlrc, authpgsqlrc, authldaprc, and userdb (together
   with the .dist versions). This works only as long as Courier was installed
   in one of the known default installation directories. The documentation in
   courier-authlib explains what to do if the existing version of Courier is
   installed in a non-default location.

   In any case, after upgrading to 0.48 these configuration files in
   Courier's configuration directory will no longer be used. To avoid future
   confusion the old copies of these configuration files (including the .dist
   files), should be removed from Courier-IMAP's configuration directory.
   They now live in Courier-authlib's configuration directory
   (/usr/local/etc/authlib, or whatever was specified to Courier-authlib's
   configure script).

  Upgrading from Courier 0.45.4 or earlier.

   The command to start the webmail server daemon has changed. The system
   startup script must be modified to run the new command:
   "/usr/lib/courier/sbin/webmaild start". Additionally, this scripts also
   starts pcpd, if required. It is no longer necessary to start pcpd by hand.

  Upgrading from Courier 0.44.0 or earlier.

   Version 0.44.1 introduced an updated webmail implementation. The suid
   cgi-bin binary has been replaced by a combination of a stub and a daemon
   process. After upgrading to 0.44.1 you will need to modify your system
   startup script to run /usr/lib/courier/libexec/courier/sqwebmaild start.
   See below for more information.

  Upgrading from Courier 0.42.2 or earlier.

   After upgrading from Courier 0.42.2, or earlier, any existing mail in POP3
   mailboxes may show up as new mail, by some mail clients. This is a
   one-time event.

  Upgrading from Courier 0.42.0 or earlier.

   Version 0.43 introduced some functional changes to the LDAP, MySQL, and
   PostgreSQL authentication modules. A new DEFAULTDELIVERY setting is added
   to each module, incorporating some functionality previously done by the
   MAILDIR setting. Previously, MAILDIR served two purposes: 1) define the
   default location to the primary mailbox, relative to the account's home
   directory, 2) provide default mail delivery instructions, overriding
   DEFAULTDELIVERY in the courierd configuration file.

   Starting with this version, MAILDIR only specifies the default location
   for the primary mailbox, and this setting is now used only by the POP3,
   IMAP, and Webmail servers. The new DEFAULTDELIVERY setting specifies the
   default mail delivery instructions. Sites that previously used MAILDIR may
   now need to copy its setting to DEFAULTDELIVERY.

  Upgrading from Courier 0.34.1 or earlier.

   Version 0.35 introduced the ability to update system passwords from the
   webmail server. If you are using the authuserdb authentication module,
   rerun the makeuserdb script after upgrading to 0.35 or later.

   Prior to 0.35, the default configuration of the webmail server maintained
   a separate webmail password file. The webmail server did not have the
   logic to update system login passwords, the approach was to copy system
   login passwords into a webmail password file. Changing the webmail
   password involved simply updating the webmail password file, and life was
   good.

   In 0.35, logic was added to update the real system password file, and the
   eliminate the webmail password file. After upgrading in 0.35, it will
   probably be necessary to reset all mail account passwords on existing
   accounts, since the webmail password file is not being used any more, and
   most people have probably changed their webmail passwords.

   As the result of the password change, the default configuration script
   will now always build the authdaemond authentication module by default.
   Previously, authdaemond was built by default only if LDAP or MySQL support
   was necessary.

  Upgrading from Courier 0.29.1 or earlier.

   Version 0.30 changed the format of most configuration files. The new
   configuration file format allows configuration files to be automatically
   upgraded. The automatic upgrade feature requires that both the old and the
   new installation have preformatted configuration files. Therefore, when
   upgrading from version 0.29.1 or earlier, use the following procedure to
   upgrade the existing configuration files.

   All configuration files are installed in the same directory, "sysconfdir".
   sysconfdir is a configurable parameter, it's usually /usr/lib/courier/etc.
   sysconfdir is /etc/courier in the RPM version of Courier.

    Back up your existing sysconfdir

   Make a backup copy of your current sysconfdir, then delete the old version
   of Courier. "rm -rf /usr/lib/courier" will do nicely. All the possible
   configurable settings are in sysconfdir, everything else can simply go.

    Back up your existing sysconfdir

   Make a backup copy of your current sysconfdir. The upgrade process
   reinstalls several default configuration files; specifically
   sysconfdir/aliases/system and sysconfdir/smtpaccess/default. Any additions
   to these files will normally be lost in the upgrade, and can be restored
   from the backup afterwards. Don't forget to rerun makealiases and
   makesmtpaccess.

    Install the new version

   Follow the installation procedure in the next section (including the make
   install-configure). The following configuration files are now preformatted
   for automatic installation:

    ldapaddressbook
    esmtpd
    esmtpd-msa
    courierd
    pop3d
    pop3d-ssl
    imapd
    imapd-ssl
    ldapaliasrc
    authldaprc
    authmysqlrc
    authpgsqlrc
    authdaemonrc

   NOTE: depending upon your configuration, you may not actually have every
   one of these files installed, so just disregard the ones that are not
   present. Manually edit filename, and retype any custom modifications from
   the backup copy of the configuration file. This is a hassle, but it only
   needs to be done once. Future upgrades will be 99% automatic.

   Any custom configuration changes are generally confined to these
   configuration files only. Very rarely are any configuration changes made
   to the remaining configuration files. If necessary, they can simply be
   restored from the backup copy made in the previous step. Something to keep
   in mind is that future versions may add additional complexity to other
   configuration files, resulting in additional configuration files being
   reformatted for automatic upgrading.

Overview

   You will need the following software in order to compile and install
   Courier:

    1. The Courier Authentication Library

       The courier-authlib package must be installed and configured prior to
       installing Courier. Download the courier-authlib package from
       http://www.courier-mta.org/authlib/.

    2. A C++ compiler

       Courier is primarily developed and built with gcc. Other C++ compiler
       may or may not work. Solaris's C++ compiler is reported to work
       without any problems. There are some issues with AIX's xlC compiler,
       which mostly has to do with the C++ libraries and header files. IBM
       has released a GNU/Linux development toolkit for AIX, which may help
       in getting Courier to compile.

    3. PCRE

       The PCRE library (http:/www.pcre.org) is required.

    4. GNU make

       On the BSD platform family GNU make is usually installed as gmake.
       Simply replace 'make' with 'gmake' in the following instructions. GNU
       make is REQUIRED. Use anything else at your own risk.

    5. Perl 5

       A recent version of Perl needs to be installed.

    6. GDBM or Berkeley DB library

       Either library must be installed.

    7. FAM, the File Alteration Monitor

       FAM (http://oss.sgi.com/projects/fam/) is optional. If FAM is
       installed, it is used for an enhanced IMAP IDLE implementation that
       provides real-time folder status updates to concurrent IMAP clients
       that have the same folder opened.

    8. OpenSSL

       Support for SSL/TLS requires OpenSSL. If OpenSSL is not installed,
       SSL/TLS features are disabled.

    9. OpenLDAP

       Support for LDAP directory services requires OpenLDAP client libraries
       to be installed. If OpenLDAP is not installed LDAP directory features
       are disabled. Sometimes there's some confusion when commercial LDAP
       servers are used, which come with their own development toolkits,
       which use a different API than OpenLDAP. Even if a commercial LDAP
       server is used to provide LDAP services, OpenLDAP is still required to
       enable LDAP services in Courier. Also, note that you need OpenLDAP
       development libraries and files. On most systems, the development
       files are packaged separately, in addition to the runtime OpenLDAP
       libraries. Make sure that you have not just the runtime OpenLDAP
       libraries installed, but the development libraries as well.

       Most of the LDAP support code is already provided by the Courier
       authentication library. Some LDAP features, such as LDAP-based mail
       aliases, are implemented in Courier directly. OpenLDAP client
       libraries must be installed. If OpenLDAP is not installed, LDAP
       directory features are disabled.

   10. mgetty+sendfax, groff or troff (not tested), ghostscript, and NetPBM

       This optional software is required to send E-mail messages via fax.
       Courier will compile and install without this software, but you will
       not be able to send faxes. All packages must be installed prior to
       installing Courier, and binaries from all packages must be installed
       in the default PATH before running Courier's configure script.

       mgetty+sendfax, ghostscript, and groff, are required for basic fax
       support, which supports faxing of plain text, Postscript, and
       PDF-formatted content. It's probably possible to use the original UNIX
       troff instead of groff, but this has not been tested. Installing
       NetPBM adds the ability to fax GIF, JPEG, and PNG images.

   The typical sequence of commands to install Courier is as follows. Read
   the following section before running these commands:

    ./configure [options]
    make
    make check       # Optional -- see below
    make install
    make install-configure

   These commands are described in greater detail in the following sections.

   ---------------------------------------------------------------------------

     If you're using gmake (the make on GNU/Linux, and gmake everywhere
     else), and you are compiling Courier on a workstation with multiple CPUs
     and plenty of memory, set the following environment variable:

    MAKEFLAGS="-j 4"; export MAKEFLAGS         # Bourne or Korn shell

     or:

    setenv MAKEFLAGS="-j 4"                    # The C shell

     This must be done before running the configure script. This works only
     with gmake.

   ---------------------------------------------------------------------------

     Courier will not work on a Linux kernel that's been patched with the
     Openwall security patch in its default configuration. The current
     version of the Openwall patch has a non-default option that turns off
     the portion of the Openwall patch which prevents Courier from running.

     NOTE: Linux-Mandrake includes the Openwall patch in the alternative
     "secure" kernel package. Courier will not run on Linux-Mandrake under
     the alternative "secure" kernel. This package must be removed and the
     standard kernel package must be installed.

   ---------------------------------------------------------------------------

Preparing for installation

   The first step consists of gathering some information about your existing
   mail system. Before proceeding, you will need to identify and resolve the
   following issues:

     * Maildirs or mailbox files

   Courier can be used as a simple mail relay -- which does not store any
   mail locally but is merely a gateway between internal and external mail
   systems. Courier can also be used as a traditional mail server, accepting
   and storing messages in individual mailboxes that are accessible via POP3,
   IMAP, or webmail.

   Courier defaults to storing mail in maildirs, not traditional flat file
   mailbox files. Maildirs require less I/O and CPU resources; they do not
   use locking; and multiple clients can read and write from maildirs
   simultaneously. Maildirs scale very well to servers with multiple CPUs.
   Some benchmark numbers on maildirs are available from
   http://www.courier-mta.org/mbox-vs-maildir/.

   Additionally, Courier's integrated POP3, IMAP, and HTTP/webmail servers
   support maildir mailboxes only. They do not support mailbox files.

   If you have an existing mail server in service, chances are that your
   current mail server delivers mail to mailbox files. You should consider
   migrating and converting to maildirs, but this will require that you also
   upgrade your POP3 server, your IMAP server, and all your other mail
   clients to software that supports maildirs. Fortunately, Courier already
   includes a fully integrated POP3 and IMAP server.

   Still, if circumstances absolutely require for you to stick with mailbox
   files, Courier has limited compatibility support for delivering mail to
   mailbox files, but you have more homework to do:

     * What locking mechanism is used on mailbox files

   If you decide to stick with mailbox files, you must know - of course -
   where your mailboxes are located, and what locking mechanism is being used
   by your mail software. Mailbox files require some form of locking, because
   only one application can access the mailbox file at the same time.
   Unfortunately, different operating systems use different locking methods.
   There are several possible locking strategies that can be used: so-called
   "dot-locks", or one of three possible kinds of file locking calls. You
   will need to consult the documentation for your existing mail software to
   determine what locking mechanisms you should use.

   In most cases, mailbox files are located in a separate partition, usually
   the directory /var/spool/mail. In some instances, mailbox files may be
   kept in the home directory of each individual account, and the mail is
   delivered to either $HOME/Mailbox, or $HOME/INBOX. Again, you will have to
   figure this out by yourself.

   Courier can deliver mail to mailbox files only if the default mailbox file
   is in the home directory of each individual account, and if you use file
   locking. Courier does not support dot-locks, and Courier does not support
   a separate mail directory for mailbox files. Mailbox files must be located
   in the home directory of each individual account.

   Courier can use a recipient database (userdb) that can specify a
   non-default location for a recipient's mailbox. In theory, it is possible
   to point each account to its individual mailbox in /var/spool/mail, or
   somewhere else. However, that's a tedious task that must be done manually
   for each account, and is likely to be a major maintenance issue.

   A better solution is to use a separate local mail delivery agent. Your
   existing mail system is very likely to include a separate local mail
   delivery agent. If you already use a mail delivery agent such as procmail,
   you probably already have it set to use the correct locking mechanism for
   mailbox files, and it already knows where the mailbox files are. Courier
   will be happy to hand off all local mail to procmail, or anything else for
   the actual delivery.

   Courier source distribution includes the maildrop mail delivery agent
   which has some additional file locking options, however you'll have less
   problems if you stick with procmail in the beginning, and switch to
   maildrop after you've gained some experience configuring and installing
   Courier.

     * Create the courier user and group IDs

   You should create a new userid and groupid named "courier". That's
   optional, but highly recommended. If this is not done, Courier will
   install as user/group daemon (or some other suitable user/group id). Only
   two of Courier's daemon processes run as a superuser (and one of them is
   perpetually waiting for a non-superuser daemon process to terminate, in
   order to restart it). Everything else runs as a non-superuser process.
   Ideally, you should reserve a separate user and group ID for Courier's use
   only, so a compromised mail system cannot be used to compromise the rest
   of the system. If push comes to shove, you can set up Courier to use a
   well-defined existing user and group ID, such as daemon.

     * Define the installation directory

   Courier, by default, installs in /usr/lib/courier. Everything goes in
   there: binaries, scripts, configuration files, and manual pages. You will
   have to configure your man command to look for manual pages in
   /usr/lib/courier/man by adding this directory to the MANPATH environment
   variable. You will also need to add /usr/lib/courier/bin and
   /usr/lib/courier/sbin (for the root user only) to the default PATH. The
   Courier RPM package installs a script that automatically implements that.

   Note that this installation layout is nothing more than a basic default,
   chosen because this simple arrangement works for everyone. The
   installation layout can be easily changed. For example, binaries can go to
   /usr/local/bin, and configuration files to /usr/local/etc. But keep in
   mind that Courier consists of several hundred individual files (at the
   last count), so if you install Courier somewhere else it might be very
   cumbersome to keep track of where everything went, and it will lead to
   almost guaranteed problems later, when you upgrade.

   You should try to use some kind of a packaging system in order to keep
   track of your Courier installation. Once you choose a packaging system,
   you should stick to it. If you switch to a different packaging system you
   should take extreme care to remove your previous package, and install your
   new package. Extreme configuration flexibility means that different
   packages will install in different places, and even have different file
   ownerships!

   For example, Courier's source code tarball can be built by RPM version
   3.0.3 or higher, into a binary RPM package. The binary RPM package
   installs configuration files in /etc/courier, the mail queue in
   /var/spool/courier, and everything else in /usr/lib/courier. If you
   install my package, and later decide to either create your own package or
   use someone else's, you will have to make sure to use the same settings,
   or remove my package completely, before installing your new package. I
   mean it when I say "remove my package completely". That includes the mail
   queue containing any unsent messages. Courier will not function if you
   reinstall it using a different user/group ID, or if you use a different
   value for any other option.

     * Conclusion

   Once these issues are squared away, you are ready to configure and install
   Courier.

OPTIONAL: Install the Socks 5 client toolkit

   Courier has the ability to send outgoing SMTP mail through a Socks 5
   proxy. The Socks 5 proxy option requires a separate module to be installed
   before installing Courier. Download the Socks 5 proxy client library from
   http://www.courier-mta.org/download.php#sox and follow its installation
   instructions. Binary RPMs can be built from the source code tarball by
   following the procedure outlined in
   http://www.courier-mta.org/FAQ.html#rpm using the "courier-sox-version"
   tarball, and installing the "courier-sox" and "courier-sox-devel" binary
   RPMs afterwards.

     NOTE: Be sure to read the README, NEWS, and INSTALL files in the Courier
     Socks 5 library toolkit, before attempting to install it for the first
     time (unless using the RPM build method).

   Socks proxying must be implemented in relatively low-level manner, and may
   not work on all operating systems. This is why it is packaged separately,
   in case that it doesn't work. The configure script, described in the
   following section, enables Socks 5 support automatically if the Courier
   Socks 5 proxy client library is already installed. To make sure that the
   library is installed correctly, specify the "--with-socks" option to the
   following configure script. This option aborts the configure script if it
   does not detect the Courier Socks 5 proxy client library.

Run configure

   After you are squared away with the preliminaries, run the configure
   script:

   ./configure [ options ]

     NOTE

     You MUST run the configure script as normal user, not root. Did you
     extract the tarball as root? It won't work. Delete everything you have
     just extracted, as root. Log in as a normal user. Extract the source
     code as a normal user, then run configure. You will do everything as a
     normal user, except for the final step of installing the compiled
     software. When you're ready to do a make install, later, su yourself to
     root, and run make install.

   The configure script can take a while to complete. There will be more then
   thirty separate configuration scripts that will be executed by this
   command. To an untrained eye it may seem that the same configuration
   script is stuck in a loop; that's because all these configuration scripts
   share a lot of code. It may take as much as 15-20 minutes for configure to
   finish on a slow machine - even more.

   You must have the uux command in your default search path if you intend to
   use Courier to relay mail via UUCP. You may need to modify your PATH
   environment variable to include the directory containing uux.

   gcc/egcs is officially blessed for building Courier. In most cases there's
   no need to tweak any compiler-specific settings. Note that there currently
   may be some unresolved issues with gcc 2.96. gcc 2.91 has been tested and
   known to work. Occasionally some of your system libraries may be stuck in
   some oddball directory that is not searched by default. Non-standard
   options for the compiler or linker can be set by putting them into
   environment variables. This must be done before running the
   configurescript:

     * CFLAGS

       Additional flags for the C compiler.

     * CXXFLAGS

       Additional flags for the C++ compiler.

     * LDFLAGS

       Additional flags for the linker.

     * LDADD

       Additional libraries to link with. NOTE - everything will be linked
       with these libraries.

   The complete reference to all configure script options is provided below.
   The most important options are:

     * --prefix=pathname

       Install Courier in pathname, instead of the default location of
       /usr/lib/courier. Note - the examples in the rest of this text assumes
       this is where you will install Courier. Do not attempt to install
       Courier in a directory whose name contains spaces or punctuation
       marks. Periods or dashes are fine, but refrain the temptation to use
       other, exotic, punctuation.

     * --with-db=db or --with-db=gdbm

       Courier requires either the GDBM or the DB database library. GDBM is
       used if both are present. This option forces the selection of the
       database library.

     * --with-locking-method=function

       Select a file locking function. Available functions are: fcntl, lockf,
       and flock. Not every function is available on every platform. If this
       option is not present, configure tries each one, and takes the first
       one that works. You can select a specific locking function by using
       this option. This affects both the locking used for delivering mail to
       mailbox files, and for other kinds of locking that Courier uses
       internally.

     * --enable-mimecharset=charset

       Specify the default character set Courier uses when adding MIME
       headers to a message. If not specified, us-ascii is used.

     * --without-tcpddns

       Use this option if you are running a small network without access to a
       DNS server. This option will cause couriertcpd to use the system
       resolver's gethostby functions instead of issuing DNS queries. Also:
       you must initialize the esmtproutes control file with the IP addresses
       of all your servers.

  configure reference

   Here's a comprehensive list of options for the configure script. They are
   presented in no particular order. In almost all cases, the configure
   script will automatically figure out the correct values, but sometimes it
   is necessary to specify them explicitly. If you ever have a need to
   manually specify any configuration option, try to determine whether you
   need it because of a particular unique case that involves your server
   only, or whether it affects any server running your hardware, or system.
   In the later case, try to investigate if it's possible for configure to be
   a bit smarter and make the right decision.

     * --prefix=pathname

       Install Courier in pathname, instead of the default location of
       /usr/lib/courier. Note - the examples in the rest of this text assumes
       this is where you will install Courier.

     * --exec-prefix=pathname

       Specify where Courier's machine-executable binaries should be
       installed. This defaults to the same directory as given by the
       --prefix option. There will be three subdirectories created underneath
       exec-prefix: bin - user-executable binaries; sbin - superuser-only
       binaries; libexec - other binaries that are not directly invoked from
       the command line, but are started by other Courier commands.

     * --bindir=pathname, --sbindir=pathname, --libexecdir=pathname

       These options override the default value for the corresponding
       subdirectory underneath --exec-prefix (see above). The bindir
       directory contains programs that can be executed by anyone. sbindir
       contains programs that can only be executed by the superuser.
       libexecdir contains programs and libraries that cannot be directly
       executed from the command line. The default locations are the bin,
       sbin, and libexec subdirectories underneath the directory specified by
       exec_prefix.

     * --datadir=pathname

       Specify the directory where miscellaneous shell scripts, Perl scripts,
       and data files will be installed. This option defaults to the
       subdirectory "share" in the directory specified by the --prefix
       option.

     * --sysconfdir=pathname

       Specifies the directory where Courier's configuration files are
       installed. This option defaults to the subdirectory "etc" in the
       directory specified by the --prefix option.

     * --localstatedir=pathname

       Specify the directory that will hold the mail queue, and other
       temporary data. This option defaults to the subdirectory "var" in the
       directory specified by the --prefix option.

     * --without-ipv6

       Do not compile IPv6 support. IPv6 support, if available is normally
       automatically detected and enabled. Use --without-ipv6 to disable it.
       IPv6 implementations on various platforms is still in flux, and IPv6
       support will not be enabled if the detection logic fails. Use
       --with-ipv6 in order to fail the configuration stage if IPv6 is not
       detected, instead of silently continuing with IPv4 support only. See
       "IPv6" below for more information.

     * --with-db=db or --with-db=gdbm

       Courier requires either the GDBM or the DB database library. GDBM is
       used if both are present. This option forces the selection of the
       database library.

     * --with-locking-method=function

       Select a file locking function. Available functions are: fcntl, lockf,
       and flock. Not every function is available on every platform. If this
       option is not present, configure will choose the first locking
       function that's available. You can select a specific locking function
       by using this option. This affects both the locking used for
       delivering mail to mailbox files, and for other kinds of locking that
       Courier uses internally.

     * --enable-mimecharset=charset

       Specify the default character set Courier uses when adding MIME
       headers to a message. If not specified, us-ascii will be used.

     * --without-tcpddns

       \Use this option if you are running a small network without access to
       a DNS server. This option will cause couriertcpd to use the system
       resolver's gethostby functions instead of issuing DNS queries. Also:
       you will have to initialize the smtproutes control file with the IP
       addresses of all your servers.

     * --without-explicitsync

       Normally Courier will automatically sync, or flush out all file
       buffers to disk, at certain key points in order to try to minimize the
       extent the mail queue can get corrupted if the system crashes. If the
       mail queue is installed on a reliable disk array or a network file
       server, this may not be necessary, and will only serve to slow down
       the mail delivery. Use this option to turn off syncing.

     * --with-dirsync

       Also explicitly sync the parent directory. There's a school of thought
       which believes that the Linux ext2 filesystem requires the parent
       directory to also be synced, in addition to the new message file
       that's just been written to disk. There's another school of thought
       that thinks that this issue is completely blown out of proportion, and
       is really nothing more than a tempest in a teapot. However -- to
       accomodate the former school of thought -- this option adds a little
       bit of extra code to sync the parent directory.

     * --with-shellpath=path

       Specify the contents of the PATH environment variable that is
       inherited by custom programs started by Courier to deliver messages.
       If not specified, PATH will be set to /bin:/usr/bin:/usr/local/bin.

     * --disable-local-extensions

       Normally, in addition to accepting mail that's addressed to
       <user@domain.com>, Courier can accept mail that's addressed to
       <user-xxx@domain.com>, for arbitrary values of xxx. In order for that
       to happen the user has to create a special file with delivery
       instructions. See the dot-courier(5) manual page for more information.
       This option disables this feature.

     * --with-paranoid-smtpext

       Be paranoid when negotiating Courier-specific ESMTP extensions with
       remote servers. The Courier mail server defines and implements certain
       experimental ESMTP extensions: XVERP and XEXDATA. Problems may result
       in the event that someone else uses the same name to implement some
       other extension. If this option is specified, Courier's ESMTP server
       will also advertise a dummy ESMTP capability called
       XCOURIEREXTENSIONS, and will not recognize any Courier-specific
       extensions unless the remote mail server also advertises this dummy
       ESMTP capability.

     * --enable-workarounds-for-imap-client-bugs

       There are several confirmed bugs in some IMAP clients that do not
       properly implement the IMAP4rev1 protocol. This option enables some
       workarounds for those buggy IMAP clients. NOTE: make check will fail
       if this option is used. You should first configure without this
       option, and if all post-configuration tests succeed, rerun configure
       with this option and recompile.

     * --with-qdircount=n

       Set n to be the number of mail queue subdirectories. In order to
       improve the speed of access to the mail queue, messages are stored in
       subdirectories, hashed by the message queue number. n specifies how
       many subdirectories will be created. If this option is not specified,
       100 subdirectories will be used. WARNING: once you've installed
       Courier once, if you decide to reconfigure and reinstall, you MUST use
       the same subdirectory count (by default, or explicitly), otherwise
       you'll end up with a big mess on your hands if you have ANY messages
       in the mail queue. If you need to change this option, wait for all
       messages in the queue to be flushed out, and reinstall with an empty
       mail queue.

     * --with-random=/dev/path, --without-random

       Sometimes Courier sometimes needs a good source of random noise. If
       configure finds /dev/urandom, it will use that. If your random device
       is named otherwise, specify it using this option. If you don't want to
       use a random device, specify --without-random, and Courier will
       generate some noise on its own. Courier will generate noise based on
       the output of a random ps command, and several other, hopefully
       unpredictable, sources.

     * --without-certdb

       Do not install a default set of trusted X.509 root CA certs (in order
       to validate the remote server's X.509 certificate). See "Configure
       ESMTP authentication and SSL" for more information.

     * --with-certdb=pathname

       Do not install the default set, but put pathname as the default
       location of the root CA database, into the configuration file. This is
       a convenient option to have Courier use an external, previously
       installed, root CA database.

     * --with-waitfunc=wait, --with-waitfunc=wait3

       Specify the system call to use to asynchronously reap child processes.
       This is a sticky one, because the behavior of the wait and wait3
       system calls varies greatly depending on the level of each individual
       system's POSIX compliance. The configure script will attempt to
       compile and run some test programs in order to attempt to figure out
       which system call actually works. If the configure script fails, or if
       it selects a wrong function (which will be evident when mail delivery
       stops, and you have a bunch of zombies that are not being reaped), you
       might have to manually specify it using either option. In that case,
       however, you should also examine the test programs, investigate what
       went wrong, and patch the test programs to give a correct result for
       your system.

     * --without-ispell, --with-ispell=program

       Courier's webmail server can use spell checking, if the ispell program
       is available (aspell can be used too). If configure finds ispell,
       spell checking is enabled. Use --without-ispell to forcefully disable
       spell checking. If ispell is not in the current search path, use
       --with-ispell=program to explicitly set the location of ispell. See
       "Configure the webmail server" for more information on ispell or
       aspell.

     * --disable-utf7-folder-encoding

       Use this option if you will not have IMAP access to mail accounts, and
       provide only webmail access. IMAP mail clients use modified UTF-7 to
       encode high 8-bit characters in folder names. If there will not be
       IMAP access to mail accounts, modified UTF-7 support in the webmail
       served can be removed, saving a little bit of overhead.

     * --enable-unicode

       Include the ability in the IMAP server to search and sort messages in
       character sets besides the default ISO-8859-1/US-ASCII. All character
       set tables supported by Courier's IMAP server will be included. See
       "Configure the IMAP server" and "Configure the webmail server" for
       more information. Additionally, all unicode tables will also be
       included in the webmail server. Keep this in mind because the full
       unicode table set is quite large.

       The webmail server also uses unicode tables to implement modified
       UTF-7 folder name encoding (see the --disable-utf7-folder-encoding),
       additionally the webmail server will be able to translate message text
       to the local character set, if the two are different and the unicode
       tables for both character sets are available.

     * --enable-unicode=charset,charset,...

       Include ability to search and sort messages, but only for these
       character sets. Also, include only these character sets in the webmail
       server. See "Configure the IMAP server" and "Configure the webmail
       server" for more information.

     * --enable-imageurl=/url

       Use /url/ as the URL to the static images displayed by the webmail
       server. HTML pages are dynamically generated by the webmail server
       CGI, but they also include some static icons. The webmail CGI will use
       /url as the URL to the directory containing the static images. The
       default URL is "/webmail", which means that the static images must be
       installed in the <DocumentRoot>/webmail directory. This is a manual
       process that is described in more detail in the "Configure the webmail
       server" section, below.

     * --enable-https, --enable-https=login, --enable-https=auto

       If you have an SSL-enabled web server, use the --enable-https option
       in order to configure webmail access for SSL. Use --enable-https=login
       in order to use SSL only when logging in, to send the password. Use
       --enable-https=auto to generate relative URLs, so that users can
       connect with either http or https and their session will remain that
       way.

       --enable-https=login and --enable-https=auto require that your http
       and https URLs that refer to the webmail CGI be identical (which is
       the usual default).

       --enable-https=auto is the default. Use --disable-https if you need to
       completely disable https, for some reason.

     * --enable-hardtimeout=7200

       set the hard timeout for webmail sessions (in seconds). The default is
       2 hours. webmail sessions are unequivocally logged out after the
       indicated time interval.

     * --enable-softtimeout=1200

       set the inactivity timeout for webmail sessions (in seconds). The
       default is 20 minutes. webmail sessions are logged out if there's no
       activity for the indicated time interval.

     * --with-defaultlang=lang

       reserved for future use.

     * --enable-mimetypes=file:file:file

       this is a colon-separated list of all of your mime.types files. The
       mime.types configuration files are used to map file extension to their
       corresponding MIME content types. The configuration script will look
       in several directories where mime.types usually exists. You can use
       this option to explicitly specify a list of mime.types files to be
       used, instead of the default.

     * --enable-bannerprog=pathname

       advanced option that sets a banner program that the webmail server
       will execute. This program should print HTML, on standard output, to
       generate a typical banner.

     * --with-maxargsize=bytes,--with-maxformargsize=bytes

       Sets an upper limit on the size of CGI arguments. Normally there's no
       reason to modify the defaults (500,000 and 2,000,000 bytes). The
       latter is generally the maximum allowed size of an attachment. The
       former is generally the maximum allowed size of a message.

     * --with-cachedir=dir, --with-cacheowner=userid

       The webmail server uses a cache of currently active logins. The
       webmail server binary, is executed for each and every HTTP request,
       and the user's maildir needs to be quickly located each time. Because
       hitting the authentication module can be expensive (think
       MySQL/PostgreSQL/LDAP query for every HTTP request!) the webmail
       server will cache this information in order to avoid having your
       authentication server brought down to its knees. By default, the
       directory /usr/lib/courier/var/webmail-logincache will be used, owned
       by the bin user. These options can be used to specify a different
       location for the webmail login cache directory.

       If you'll be using the webmail server, you MUST add an hourly cron job
       to run the /usr/lib/courier/share/sqwebmail/cleancache.pl script which
       deletes expired cache records from the cache directory. Add the
       following command to be executed from cron at least once an hour:

 su -c "/usr/lib/courier/share/sqwebmail/cleancache.pl" bin

       (This assumes that your cache directory is owned by the bin user).
       There's no need to set up this cron job if the webmail server is not
       used. NOTE: your su command may use different options or syntax, check
       the su manual page to confirm the correct syntax.

     * --without-gzip

       if the configuration script finds the gzip utility, the webmail server
       will automatically use gzip compression for some large web pages (if
       the client browser supports gzip compression). Use this option to turn
       off gzip compression.

     * --disable-autorenamesent

       do not rename the Sent folder every month. This option can also be
       controlled by the SQWEBMAIL_AUTORENAMESENT environment variable (which
       can be set in Apache's httpd.conf, for example).

     * --with-calendarpurge=N

       if calendaring is enabled, purge expired calendar events after N days
       (default: 30).

     * --with-trashquota

       include deleted messages, and the Trash folder, in the estimated quota
       usage for maildirs. Quotas are optional, see the file
       maildir/README.maildirquota.html for more information. The default
       configuration does not count messages marked as deleted (but not yet
       expunged) and the contents of the Trash folder (which are
       automatically purged by the server) against the quota usage. NOTE - if
       this option is used, make check WILL FAIL. You should first configure
       Courier without this option, run make check, then reconfigure Courier
       with this option.

IPv6

   IPv6 support in Courier means basically the following:

     * ESMTP, IMAP, and POP3 servers will create an IPv6 socket and accept
       IPv6 connections.
     * The ESMTP client will attempt to resolve AAAA records in addition to A
       records.
     * Headers in incoming mail will log IPv6 addresses, instead of IPv4
       addresses. Delivery Status Notifications and log files will also
       reflect IPv6 addresses.

   IPv6 implementations are required to accept IPv4 connections on IPv6
   sockets, so IPv6 sockets should be able to receive both IPv4 and IPv6
   connections. In the event that your IPv6 implementation is not stable, or
   is partially incomplete, IPv6 support in Courier should be disabled.

   The configuration script will attempt to detect whether IPv6 structures
   and functions are available, and automatically enable IPv6 support if they
   are found. The --without-ipv6 option disables IPv6 support, which may be
   desired for the following reasons:

     * The IPv6 implementation on your platform is incomplete.
     * The IPv6 implementation on your platform is actually not available,
       despite the presence of IPv6 structures and functions. Most GNU/Linux
       distributions ship without IPv6 support enabled in the default kernel
       build. Courier automatically falls back to creating an IPv4 socket, if
       it can't create an IPv6 socket, so things should continue to work in
       that case. However, each such attempt is likely to result in an error
       message logged to /var/log/messages -- modprobe is whining that it
       can't find an IPv6 module to load. On systems that handle a large
       amount of traffic the log files can fill up rather quickly.
     * Implementing IPv6 can increase the amount of DNS traffic, even if
       there is no IPv6 support in the kernel. Even if Courier falls back to
       IPv4 sockets, it will continue to resolve IPv6 addresses, resulting in
       some extra DNS queries. There won't be a lot of extra DNS queries, but
       there will be some. Also, there are still some DNS servers that cannot
       correctly handle IPv6 queries, and attempts to deliver mail to these
       domains will fail despite the presence of valid IPv4 records.

   IPv6 support is still a bit spotty in some places. If the configuration
   checks fail, IPv6 support will be quietly suppressed. If you expect IPv6
   support to be present, the --with-ipv6 flag can be used to abort
   configuration if IPv6 support was not detected.

Compile and run make check

     make
     make check

   If the configure script ran without errors, run make to build Courier. If
   make completes succesfully, run make check. make check runs some simple
   internal tests. It is not feasible to run a complete check of Courier's
   behavior, but make check does automatically run some tests on several
   modules.

   If make check fails, you need to do some detective work. Investigate the
   source of the failure. It is possible that the issue can be resolved by
   specifying different options to the configure script, in which case you
   have to go back and rerun the configure script again.

Installation

   su yourself to root, if you want to do a live install, then run make
   install or make install-strip to install Courier. If you use the GNU
   version of make, and you would like to see which files Courier installs
   and where, don't su yourself to root, but set the make variable named
   DESTDIR. For example:

   make install DESTDIR=/var/tmp/courier-inst

   The contents of DESTDIR are prepended to the name of every file installed,
   so if --prefix was set to /usr/lib/courier, the files will be installed in
   /var/tmp/courier-inst/usr/lib/courier. This only works if you use GNU
   make.

   NOTE: you must make sure that your umask is 022 before you run make
   install.

   If executed by root, make install automatically sets the correct ownership
   on the installed files. Non-root make installs do not set the ownership,
   but still set correct permissions. This feature is mainly for use by
   people who are rolling Courier into a prebuilt package, since this allows
   them to build the package as a normal user, not root. In this situation
   the command make install-perms will be very useful. This command creates a
   file called permissions.dat. This file contains a complete listing of
   everything that will be installed, and what the correct permissions are on
   every file.

   make install installs Courier binaries with debugging data, which is
   probably a good idea to do while Courier is in development. Use
   makeinstall-strip to install binaries without debugging data. Some systems
   have a broken install utility, so make install-strip may fail.

Install configuration files

   The following command creates and updates configuration files. It must be
   executed after running make install:

   make install-configure

   This command copies each configuration file "filename.dist" to "filename".
   The existing filename is backed up as filename.bak. If upgrading from
   Courier 0.30 or later, the previous configuration settings in filename.bak
   will be automatically copied to filename, provided that they are still
   valid. If a configuration setting may no longer be valid, it will be reset
   to its default value. The output of make install-configure will indicate
   the status of each configuration setting, therefore it is advistable to
   save the output to a file, and examine it:

   make install-configure >upgrade.log

   Versions prior to 0.30 cannot have their configuration settings
   automatically preserved, and must be restored manually from filename.bak.
   Do not simply copy filename.bak to filename, this will lose all the
   formatting codes that allow automatic upgrades.

  PAM configuration

   If you use PAM library for authentication, you may need to set up PAM for
   authenticating POP3 logins, IMAP logins, webmail logins, and/or ESMTP
   authentication. In most cases, all you have to do is install
   /usr/lib/courier/etc/pop3d.authpam as /etc/pam.d/pop3,
   /usr/lib/courier/etc/imapd.authpam as /etc/pam.d/imap,
   /usr/lib/courier/etc/webmail.authpam as /etc/pam.d/webmail, and
   /usr/lib/courier/etc/esmtp.authpam as /etc/pam.d/esmtp. However you will
   have to consult your PAM documentation, and the manual pages for authpam,
   in order to make sure.

   Some versions of the PAM library, do not use the /etc/pam.d directory.
   Instead they use a single configuration file /etc/pam.conf. Here's an
   example of what needs to be added to /etc/pam.conf on FreeBSD 4.0. NOTE:
   other platforms may need something similar:

 imap  auth    required        pam_unix.so      try_first_pass
 imap  account required        pam_unix.so
 imap  session required        pam_permit.so
 pop3  auth    required        pam_unix.so      try_first_pass
 pop3  account required        pam_unix.so
 pop3  session required        pam_permit.so
 esmtp auth    required        pam_unix.so      try_first_pass
 esmtp account required        pam_unix.so
 esmtp session required        pam_permit.so

  Building RPM packages

   NOTE: If you build an RPM package directly from the source tarball, the
   resulting RPMs may not install if you have an existing IMAP or an existing
   POP3 server installed. The RPM packages will contain these PAM
   configuration files, and they will conflict with any PAM configuration
   files installed by another IMAP or POP3 server. If you manually installed
   an IMAP or a POP3 server without packaging them up into an RPM, the
   Courier RPM package will install and the old configuration files will be
   silently removed, since they were not installed using RPM.

   Courier includes integrated POP3, IMAP, and webmail servers, however they
   only work with maildirs. Decide if you want to keep using your current
   server, or switch to Courier's IMAP/POP3/webmail servers. If you want to
   keep your existing servers, back up the contents of your /etc/pam.d
   directory before installing the RPM, install it, then restore the
   overwritten files. If you want to switch to Courier, blow away your
   current server before running make install.

Adjust system paranoia level

   There are four setuid binaries in Courier that are owned by root:
   sendmail, maildrop, webmail and webadmin. There's also one setgid binary,
   sqwebpasswd.

   /usr/lib/courier/bin/maildrop is the mail filter. If you do not need mail
   filtering, you can remove it. The setuid root privilege is only needed to
   implement mail filtering "on the wire", when receiving mail from an
   external mail relay (see localmailfilter(7) for more information).
   Removing the setuid root bit still allows traditional mail filtering to be
   used, after the message is received and delivered to the mailbox.

   /usr/lib/courier/libexec/courier/webmail/webmail is the webmail CGI. It is
   executed by the web server, and needs to change its userid/groupid, in
   order to enter the maildir. If you do not need webmail access, you can
   remove it. An alternative is to implement virtual mailboxes, owned by a
   non-privileged userid, and change the ownership of the webmail CGI to the
   non-privileged user (you will also need to use the --with-cacheowner
   option to the configure script since the webmail process must have write
   access to the webmail login cache directory).

   /usr/lib/courier/libexec/courier/webmail/webadmin is the wrapper for the
   web-based administration tool. See below for more information.

   /usr/lib/courier/bin/sendmail is the command line mail sender. Its first
   order of business is to set its group id to Courier's group id, and
   restore the original userid, dropping root. The reason that it needs root
   setuid is to set its real group id, because setting the setgid bit on the
   executable is not enough. The setgid bit sets only the effective group id,
   and the root setuid bit is required to set both effective and real group
   ids. Both real and effective group IDs are needed in order to be able to
   implement maildrop mail filtering.

   /usr/lib/courier/libexec/courier/sqwebpasswd is described in detail in the
   "OPTIONAL: Changing mail account passwords using the webmail server"
   section.

Post-installation setup

   A first-time Courier installation may not require the system startup
   scripts to be modified to start Courier at system boot. Until the system's
   functionality is verified, the system will probably continue to use the
   existing mail server. Still, most Courier configurations will require two
   things to be started before any part of the system is put to use:

     * An hourly cron job needs to be created to run the cleancache.pl
       script, which purges expired webmail login cache records. Logging in
       to the mail account via the web creates a file in a temporary
       directory that caches the login session identity. The output of make
       install includes the command that needs to be set up as a cron job by
       root. The cron job runs su to change to the userid that owns the login
       cache directory, then runs the purge script. The su command on some
       system uses a slightly different syntax than what's shown by make
       install. It may be necessary to consult the su man page before setting
       up the cron job. Run the su command as root, to make sure that its
       syntax is correct, before setting up the cron job. The cron job can be
       omitted if webmail is not going to be used.

Post-installation checks

   The following tests should be run to verify that your installation works
   properly. These tests are not really comprehensive tests, they only make
   sure that the basic functionality is there, and they definitely must be
   done the first time you install a version of Courier on your system. If
   you later reinstall the same version on the same platform, using the same
   configuration, you don't need to run these installation checks (but you
   better be sure that the reinstallation is COMPLETELY identical to the
   original install). You might also wish to rerun these installation checks
   after upgrading your base operating system.

   The following documentation assumes that Courier is installed in
   /usr/lib/courier.

  Verify module installation

   Run the showmodules utility after all files have been installed, but
   before you attempt to start Courier. The showmodules utility attempts to
   load and initialize transport modules that have been configured, without
   actually starting up Courier. Running showmodules should result in
   something that looks like this:

 \001\001 showmodules[5060]: Loading STATIC transport module libraries.
 \001\001 showmodules[5060]: Installing i586-gnu-linux [0/0]
 \001\001 showmodules[5060]: Installing local
 \001\001 showmodules[5060]: Installed local
 \001\001 showmodules[5060]: Installing esmtp
 \001\001 showmodules[5060]: Installed esmtp
 \001\001 showmodules[5060]: Installing dsn
 \001\001 showmodules[5060]: Installed dsn
 \001\001 showmodules[5060]: Initializing local
 \001\001 showmodules[5060]: Initializing esmtp
 \001\001 showmodules[5060]: Initializing dsn

  Test child process termination

   In this test, you will start Courier, then attempt to rapidly pump through
   as many messages as fast as possible, to verify that asynchronous child
   process termination handling works. For this test (and the following
   tests) you need to use a test account.

   Log on to the test account and run maildirmake to create two maildirs:
   maildirmake $HOME/test, and maildirmake $HOME/bounces.

   Create $HOME/.courier-test-default, containing one line: ./test. Create
   $HOME/.courier, containing one line: ./bounces. If you previously selected
   .qmail compatibility, you will need to use .qmail-test-default and .qmail,
   of course. Keep that in mind as you work through the remaining tests.

   Start Courier as root:

   /usr/lib/courier/sbin/courier start

   Check your system log files for any error messages. Run the ps command,
   and check that you only have the following processes running: courierd
   (two processes), courierdsn, courieruucp, courieresmtp, and courierlocal.
   You will also have a couple of "logger" processes hanging around, that's
   ok too.

   One of the two courierd processes will be running as root. The
   courierlocal process will also be running as root. All other processes
   will be running as the courier (or daemon, or mail) user. courieruucp may
   be running as uucp.

   Run the perftest1 script, which can be found in the directory containing
   Courier's source code:

 sh perftest1 1000 "user-test-1 user-test-2 user-test-3 user-test-4 user-test-5"

   Run this script while logged on to the test account. Replace "user" with
   the name of your test account. This will send 1000 messages with five
   recipients per message. You should end up with exactly 5000 messages in
   $HOME/test/new. Count them.

   Monitor the system logs. There will be a lot of activity. On my test
   system, the system logger usually backs up. Courier generates log messages
   faster than the logger can record them. When all the activity stops, count
   how many files you have in $HOME/test/new. For extra credit, total up the
   Delivered-To: headers in all the messages, there should be 1000 headers
   for each one of the five addresses.

   If you did not get 5000 messages, and mailq comes up empty, check
   $HOME/bounces/new. If you're lucky, the rest bounced. That's still a
   problem, but the bounces will help you to investigate things further.

   If you did not get 5000 messages, and mailq shows some messages remaining
   in the queue, and ps shows some dead zombie processes that are not being
   reaped, this means that asynchronous process termination is not working.
   You will need to examine your configuration to see whether configure
   selected the wait or the wait3 function. Unpack the source code again and
   rerun configure. This time use the --with-waitfunc option to choose the
   other wait function, manually. Recompile, reinstall, and rerun this test.

   If you did get all the messages, go through your syslog for extra-extra
   credit. grep it for the word "defer" to see if any messages required
   multiple delivery attempts. This shouldn't happen either.

   If your hardware has enough juice to pump through 5000 messages in a short
   period of time, rerun this test with a larger number of messages. Before
   doing that, wipe the Maildirs clean, in order to confirm the message
   count, later. The test must run for at least 3-4 minutes in order to get
   meaningful results.

  User/group ID check

   For this test you will need to use or create a regular user test account,
   which will be referred to as user. You can use the same test account you
   used in the last test, but erase all .courier (or .qmail) files.

   In user's home directory, create .courier which contains the following
   text:

 | /usr/bin/id >ID
 | /usr/bin/env >ENV

   Make sure that your id and env commands are in /usr/bin. If not, use the
   correct path.

   Send a single message to user:

   echo "To: user" | /usr/lib/courier/bin/sendmail

   Thie message will disappear into the never-never land, so don't waste time
   looking for it. Just examine, very closely, the contents of the ID and the
   ENV files in user's home directory. Double check what user and the group
   ids recorded in ID match user's. Pay close attention to any auxiliary
   group IDs, make sure that they haven't "leaked" from the root user who
   started Courier.

   Also, examine the environment, in ENV. Check the manual page for
   dot-courier, ENV should contain only the documented environment variables,
   and any environment variables that are defined in the
   /usr/lib/courier/etc/courierd file.

OPTIONAL: Configure webadmin

   This is a web-based administration tool. webadmin is a web CGI
   application. It is necessary to have a local web server installed in order
   to use webadmin. Apache will do, but so will any other server with a
   complete CGI implementation (PHP is not required). Installing webadmin is
   a three step process:

    1. Move /usr/lib/courier/libexec/courier/webmail/webadmin to your web
       server's SSL cgi-bin directory. Take care to preserve the binary's
       ownership and permissions.
    2. Execute "make install-webadmin-password". This prompts for a password,
       which is saved in the file /usr/lib/courier/etc/webadmin/password.
    3. The web server SHOULD be configured to run webadmin from the cgi-bin
       directory using SSL only. webadmin's authentication is rather simple:
       the password is saved in a cookie. Unless SSL is used, the webadmin
       password can be intercepted in transit. If SSL is not available, an
       acceptable level of security can be achieved by setting up a firewall
       that allows web access only from trusted IP addresses, then use a
       dedicated webadmin password. This is not perfect, but is generally
       adequate. A firewall is a good idea even if SSL is used. This is not
       Fort Knox, and webadmin is not going to be publicly accessible, so the
       only needed security is to keep everyone out except for authorized IP
       addresses.

       Note that webadmin, by default, will enforce this restriction: either
       SSL, or access from a local IP address. Create the file
       /usr/lib/courier/etc/webadmin/unsecureok to allow non-SSL webadmin
       connections from remote IP addresses.

   webadmin is designed to be self-explanatory. Configuration options are
   divided into logical sections. Changes made to configuration options do
   not take effect immediately. To apply configuration changes, select
   "Install new configuration" from the main menu. To cancel all changes
   made, select "Cancel new configuration". Selecting "Install new
   configuration" will apply all the changes to the configuration files, and
   restart any Courier modules that must be restarted in order for the
   changes to take effect.

   If you decide to use webadmin, most of the remaining steps in this INSTALL
   document can be done using webadmin's equivalent screens.

Create system aliases

   You must now specify which account gets postmaster mail. Courier does NOT
   deliver any mail to root. You must use a non-privileged for postmaster
   mail. You will also need to specify where your postmaster account is. In
   the following example the same account is used for both, but you can
   easily use separate mailboxes.

   Let's say that you want postmaster mail to be delivered to the user
   "admin".

   Create /usr/lib/courier/etc/aliases/system using any text editor. An
   example aliases/system file is created by make install, and you can simply
   edit what you have there. The default contents of this file are as
   follows:

   root: postmaster

   mailer-daemon: postmaster

   MAILER-DAEMON: postmaster

   uucp: postmaster

   You need to append the following line:

   postmaster: admin

   These aliases cause all mail addressed to root, postmaster, or
   mailer-daemon, to be delivered to admin's account. If you want root's mail
   delivered somewhere else, you can replace "root: postmaster", with
   something else.

   Run the following command as root:

   /usr/lib/courier/sbin/makealiases

   This command creates /usr/lib/courier/etc/aliases.dat, a database that
   contains your new aliases.

   Send a test message:

   echo "To: postmaster" | /usr/lib/courier/bin/sendmail

   Check admin's mailbox, the message should be there.

   Let's do it again:

   echo "To: postmaster" | /usr/lib/courier/bin/sendmail -Nsuccess

   This time, in addition to the blank message, the sending account should
   receive a return receipt.

   Additional aliases can be either added to this file, or placed in any
   other text file in the /usr/lib/courier/etc/aliases directory.

Create smtp access list

   You need to define which IP addresses are allowed to relay SMTP mail
   through the server. The installation script creates
   /usr/lib/courier/etc/smtpaccess/default containing an example of how to
   enable relaying for IP address 127.0.0.1, and several reserved netblocks.
   You can either append additional entries to this file, or put your
   additional entries in any other file in the
   /usr/lib/courier/etc/smtpaccess subdirectory. Afterwars, run the following
   as root:

   /usr/lib/courier/sbin/makesmtpaccess

   This command creates the /usr/lib/courier/etc/smtpaccess.dat database that
   couriertcpd uses to initialize the environment for courieresmtpd.

   You will need to rerun makesmtpaccess in order to rebuild smtpaccess.dat
   after any changes in the smtpaccess subdirectory.

   The default Courier configuration applies smtpaccess.dat to both the
   regular ESMTP server (port 25), and the message submission server (port
   587). It is possible to set up different access files for both ports. To
   do that, edit /usr/lib/courier/etc/esmtpd-msa, and explicitly set
   ACCESSFILE to a different file, create that file, and use the
   makesmtpaccess-msa command to compile the dedicated port 587 access
   database.

     NOTE: Authenticated SMTP is preferred over defining explicit IP address
     ranges. When combined with SSL, authenticated SMTP enables relaying
     privileges to any sender that securely provides a valid login/password,
     from any IP address, instead of only a small range of preauthorized IP
     addresses. The "OPTIONAL: Configure ESMTP authentication and SSL"
     section, later in this installation guide, gives more information on
     enabling authenticated SMTP and SSL-based encryption.

     Furthermore, preauthorized IP address ranges are vulnerable to being a
     source of abusive backscatter E-mail. Using authenticated SMTP together
     with the optional backscatter setting, described in the following
     section, prevents transmission of abusive backscatter bounces to
     external recipients even from trusted senders that have been
     compromised.

Backscatter suppression

     NOTE: It is important to know that Courier's default backscatter
     configuration means that if Courier receives a message for delivery to a
     local mailbox, and encounters an error during the delivery, the sender
     may not receive a delivery failure notification. The most common reason
     is an error in a custom mail filtering script. The next most common
     reason is a configuration error (the Courier authentication library
     gives the account's home directory, optional non-default mailbox
     location, the account's system userid and groupid; but they differ from
     the actual files and directories (the home directory or the account's
     mailbox does not exist, exists somewhere else, or they're owned by a
     different userid or groupid).

     When installing Courier for the first time, it is usually helpful to
     termporary turn off the default backscatter filters, by setting
     BOFHSUPPRESSBACKSCATTER to "none", as described below. Remove this
     setting after Courier is installed and its basic functions appear to be
     working.

   The term "backscatter" refers to non-delivery reports sent to a forged
   return address. SMTP was created a long time ago, in better times when
   everyone trusted each other. Anyone could provide any return address for
   any E-mail message.

   Times have changed. At the time this documentation is written, most
   surveys report that between 75% and 80% of Internet E-mail is junk E-mail
   or viruses, with a forged return address.

   Backscatter becomes a problem when a mail server does not reject unwanted
   mail. The mail server decides that the message is unwanted only after it
   is accepted. It generates a non-delivery notice, and sends it to the
   original message's return address. Because viruses and junk mail use
   random forged return addresses, the unfortunate victim of address forgery
   must deal with large amounts of useless non-delivery notices from the
   mailbox. Not to mention a bunch of uninformed people who think he is
   responsible for sending the virus or the junk mail to them.

   There's now a growing consensus that backscatter bounces should be
   considered E-mail abuse. Courier is already very good at minimizing the
   amount of backscatter, by the virtue of refusing to receive any mail to a
   nonexistent local mailbox. However it's still possible for Courier to
   bounce a received message. Several settings control how Courier filters
   out its own backscatter, and avoids becoming a nuisance to others.

   Two settings are available. The first setting instructs Courier to simply
   discard backscatter bounces. This is the ESMTP_BLOCKBACKSCATTER setting in
   the courierd configuration file. This setting lists the so-called "message
   sources" which are dropped by the SMTP client. All messages from any
   matching source are quietly discarded. The default setting lists one
   message source: a code that means "a delivery status notification for a
   message received via SMTP from a non-authenticated source".
   "Non-authenticated" means a message received from an IP address that does
   not have relaying privileges, and did not authenticate. It's also possible
   to include authenticated SMTP sources; or it's possible to disable this
   setting altogether, instructing Courier to deliver all bounces via SMTP,
   even if they may potentially be backscatter.

   Note that messages received in other ways (such as messages sent via the
   sendmail command) are not affected. Their bounces will be sent via SMTP in
   all cases (although there exists an undocumented setting to block those
   bounces too). Also, bounces are always delivered to local mailboxes, this
   setting is ignored for local mail deliveries.

   The default setting means that if Courier receives a message via SMTP for
   delivery to a local mailbox, and it bounces for some reason, the bounce
   will be discarded.

   Courier is also often used as a smarthost for SMTP clients. These SMTP
   clients either connect from trusted IP addresses (IP addresses that belong
   to the organization that runs the mail server), or that succesfully
   authenticate, using SMTP authenticate. If those messages bounce, the
   non-delivery report gets delivered, because the default setting only drops
   bounces from non-authenticated source (a connection from a trusted IP
   address is always processed as if the sender succesfully authenticated).

     NOTE: Sometimes Courier serves as a backup MX for another organization.
     If mail cannot be delivered to the primary MX (it rejects the message,
     or the message times out), the bounce will be discarded, because the
     message was probably received from a non-authenticated source.

   The second setting minimizes the possibility of generating a bounce, of
   any kind, in the first place. The second setting controls the backscatter
   suppression list, which is a list of blacklisted E-mail addresses.

   When Courier fails to deliver a message to an address, this address goes
   on the suppression list, and Courier will refuse to accept any more
   messages to the same address. If the delivery failure was a temporary
   failure, any future messages will also be turned away with a temporary
   error. A permanent delivery failure results in future messages rejected
   with a permanent error.

   Note that the suppression list does not apply to messages already accepted
   by Courier, and which are in its mail queue. The suppression list is
   checked when Courier is receiving a new message. Courier automatically
   clears an address from the suppression list after two hours. If the
   original message encountered a temporary delivery failure, Courier
   periodically tries again to re-deliver the message. If the message
   continues to encounter a temporary delivery failure, the clock starts
   running again, from the beginning, If a re-delivery attempts succeeds, the
   address is cleared from the suppression list, and Courier will now accept
   more messages to the same address, immediately.

   If a message keeps encountering temporary delivery failures, the time
   before re-delivery attempts gets longer. It's possible that it could take
   more than two hours for another delivery attempt, on a busy mail server.
   The address then falls off the list, and Courier will accept another
   message to the undeliverable address. This situation is unavoidable, but
   is not considered to be a major issue.

   The second setting is the BOFHSUPPRESSBACKSCATTER setting, in the bofh
   configuration file. See the courier(8) man page for more information. The
   default BOFHSUPPRESSBACKSCATTER setting also filters only messages from
   non-authenticated SMTP sources against the suppression list.

   The suppression list is not updated when problematic messages are manually
   removed from the mail queue (using the "courier cancel" command). Even
   though the stuck messages are deleted, Courier will continue to refuse
   messages to suppressed addresses, until they time out. Use the "courier
   clear" command to manually clear addresses from the suppression list, if
   so desired.

     NOTE: A mailbox that exceeded its storage quota results in temporary
     delivery failures. Therefore, when a mailbox fills up, Courier stops
     accepting any more messages to this mailbox (there might be one or two
     messages already in the mail queue, but that shouldn't be a major
     issue). Mail deliveries will resume when the mailbox goes below the
     quota (although this may take an hour, or two, as explained previously).
     It's possible that an existing version of Courier was originally
     modified to generate a permanent delivery failure for a quota exceeded
     condition. This change should now be undone, in order for backscatter
     suppression to work properly.

   The third setting is the DSNTOAUTHADDR=1 setting in the courierd
   configuration file. This setting, when enabled, alters bounce handling of
   messages that were received from an authenticated SMTP connection.

   Bounces of authenticated messages are processed according to the previous
   two settings, except that the bounce message gets sent (if it gets sent at
   all) to the authenticated login address, instead of the message's return
   address.

     NOTE: This works only if Courier is configured, via the Courier
     Authentication Library, to validate login IDs that consist of a full
     E-mail address, "user@domain", with the login ID corresponding to the
     mailbox's E-mail address.

   Enabling this setting removes the possibility of Courier sending abusive
   backscatter bounces to external recipients, from a compromised trusted
   sender, even if the compromised trusted sender uses authenticated SMTP.
   Instead of sending the bounces to the forged return address, they get
   redirected to the sender's mailbox.

     NOTE: The authenticated address is used for bounces only. When the
     message gets sent to its listed recipients, the message's return address
     gets used, as usual.

     NOTE: Authenticated SMTP must be used for this option to have any
     effect. When relaying privileges are granted to explicit IP address
     ranges (see the preceding "Create smtp access list" section), Courier
     will not have the sender's authenticated login address (unless the
     sender voluntary authenticates).

Miscellaneous configuration

   Review/edit contents of various configuration files in
   /usr/lib/courier/etc:

     * courierd

       this file controls general aspects of Courier's message processing. A
       default file is installed with comments describing what the various
       options are. Review the default options, and make whatever changes you
       deem appropriate. You will probably need to make changes to this
       configuration file in order to select the correct way to deliver local
       mail (whether to have Courier handle the delivery directly, or whether
       to run procmail or maildrop). There are comments in this file that
       tell you what needs to be done to have Courier use a separate local
       mail delivery agent, such as procmail, for mail delivery. Read and
       follow the instructions there.

     * esmtpd

       this is an important file that controls Courier's ESMTP server.
       Options in this file include setting the maximum limit on simultaneous
       server connections, whether to disable certain optional SMTP features,
       whether or not you have a mail filter module installed, and whether or
       not blacklists are used.

     * esmtpd-msa

       this file controls Courier's ESMTP message submission server (RFC
       2476). The settings in this file supplement the settings in esmtpd.
       The default startup script first reads esmtpd, then esmtpd-msa in
       order to initialize the ESMTP message submission server on port 587.

     * smtpaccess

       this configuration file/directory is used to ban explicit IP addresses
       from connecting to the ESMTP server at all, or to specify which IP
       address ranges are allowed to relay mail through the ESMTP server. The
       default file turns on relaying in a couple of reserved IP address
       ranges, as an example. The makesmtpaccess command must be executed for
       any changes to smtpaccess to take effect.

     * pop3d

       this file sets various options for Courier's POP3 server. Courier's
       POP3 server can be used only if mail is stored in Maildirs. You will
       need to use another POP3 server if you choose to deliver your mail to
       legacy mailbox files. A default configuration file is installed,
       describing the available options.

     * imapd

       this file sets various options for Courier's IMAP server. Courier's
       IMAP server can be used only if mail is stored in Maildirs. You will
       need to use another IMAP server if you choose to deliver your mail to
       legacy mailbox files. A default configuration file is installed,
       describing the available options.

    Qmail compatibility mode.

 echo "qmail" >/usr/lib/courier/etc/dotextension

   Run this command if you are installing Courier on a system that's
   currently running the Qmail mail server. Courier will now read .qmail
   files for delivery instructions, instead of .courier files. Courier's
   .courier files are mostly compatible with Qmail's .qmail files, but there
   are some minor differences. Still, most of your .qmail files should work
   without too many problems.

Define local domains

   The configuration file /usr/lib/courier/etc/locals is a list of all the
   domains that are considered local. Mail to any address in any local domain
   is handled as a local delivery. If this file does not exist Courier will
   use the contents of the me configuration file, or it will obtain its
   machine name from the operating system.

   This file contains a list of domains, one per line. In most cases you need
   to initialize this file to contain every hostname that has a DNS A, or
   AAAA, record pointing to any IP address assigned to this machine,
   including "localhost". You will also need to include any domain that lists
   this machine as its primary MX relay.

   You may also include domain wildcards in locals by prefixing the domain
   with a period. For example: ".example.com" will treat any domain
   underneath example.com - like a.example.com, b.example.com - as a local
   domain. Note that this does not include example.com itself, so you may
   need to list it explicitly as well!

   NOTE: The makealiases command must be entered after making any changes to
   this file.

Create a list of domains to accept mail for

   If you would like your server to function as a backup mail relay for other
   domains, create /usr/lib/courier/etc/esmtpacceptmailfor. This is a plain
   text file, containing a list of domains, one per line. This file lists all
   domains your server will accept mail for. NOTE: if you create this file,
   you MUST include all your local domains. Usually you can simply append
   what you have in /usr/lib/courier/etc/locals. If
   /usr/lib/courier/etc/esmtpacceptmailfor does not exist, Courier will
   accept mail only for the machine name listed in /usr/lib/courier/etc/me,
   (or the system machine name).

   Like /usr/lib/courier/etc/locals, prepending a period to a domain name in
   esmtpacceptmailfor will cause Courier to accept mail for all subdomains of
   this domain.

OPTIONAL: Configure UUCP

   Courier is capable of sending and receiving mail via UUCP. Courier does
   not implement UUCP directly, but instead uses your existing UUCP software
   to send and receive mail.

   Courier's UUCP functionality has been tested with Taylor UUCP 1.06. It's
   likely that some minor tweaking will be necessary to get Courier working
   with other UUCP builds. Give it a shot, and keep an eye out for problems.

  /usr/lib/courier/etc/uucpme

   This configuration file must be initialized to list the UUCP node name
   that this machine is known as. Currently Courier does not support multiple
   UUCP node aliases for the same machine.

  /usr/lib/courier/etc/uucpneighbors

   This configuration file contains a list of all the nodes that your machine
   talks to via UUCP. Obviously this information will be a duplicate of the
   corresponding data in your existing UUCP configuration files, and some
   maintenance will be necessary to keep both lists in sync. That is,
   unfortunately, unavoidable. The makeuucpneighbors commands turns this
   plain text file into a database, which is what Courier uses directly. The
   format of the uucpneighbors configuration file is described in the
   makeuucpneighbors(8) manual page.

  /usr/lib/courier/etc/uuucprewriteheaders

   Courier automatically rewrites message envelope addresses from ESMTP to
   UUCP format. If this file exists, the addresses in the headers of messages
   sent to/from UUCP addresses will also be rewritten.

Configure UUCP domain aliases

   Courier can accept mail addressed to <user@example.com>, and then forward
   it to uucp!bang!path!user, via UUCP. This is done by adding a UUCP virtual
   domain alias to your aliases file, see "Create system aliases". Append the
   following entry to your /etc/aliases, then run the makealiases command:

    @example.com: uucp!bang!path!

   See the makealiases(8) manual page for more information.

OPTIONAL: Configure LDAP aliasing

   In addition to using LDAP for authentication and for managing accounts,
   Courier can use an LDAP directory for routing, or "aliasing" mail.

   The term "aliasing" refers to substituting one or more addresses for
   another address. A one-to-one substitution results in Courier accepting
   mail for one address, and delivering the mail to another address. A
   one-to-many substitution results in Courier accepting mail for one
   address, and delivering a separate copy of the message to every address
   defined by the alias.

   Courier supports a basic form of aliasing using a GDBM or DB-based
   database. The makealiases(8) command reads a plain text file containing
   the aliasing rules, the creates a GDBM or a DB database. Each recipient
   address is looked up in the database, and if an alias is defined for the
   recipient address, it is used in place of the original address. Aliasing
   can be used against individual addresses, one by one. An extended form of
   aliasing maps an entire domain to a single local address, using
   dot-courier(5) delivery instruction files.

   Courier can use an LDAP directory instead of a GDBM or a DB database, to
   perform essentially the same function. If OpenLDAP is available at time of
   installation, the installation script installs the courierldapaliasd(8)
   program and a ldapaliasrc configuration file. It will be necessary to
   enter appropriate information into ldapaliasrc, and arrange to run
   "courierldapaliasd start" at system boot time (it is a background daemon
   process that opens persistent connections to the LDAP server).

   Additional instructions for setting up LDAP-based aliasing are found in
   the courierldapaliasd(8) manual page.

OPTIONAL: Configure mail filtering

   Courier includes several options for selectively filtering mail. In
   general, Courier provides only the plug-in interfaces by which arbitrary
   external mail filters can be used to selectively accept or reject
   messages. Courier comes only with some sample code that demonstrates how
   to write a mail filter. An actual mail filter must be written and
   installed separately. Please note that running mail filters can have a
   non-trivial impact on mail system performance and throughput.

   Courier provides two mail filtering interfaces:

     * Global mail filters

       these filters are installed and will be used to filter every incoming
       message. Global mail filters are permanently running daemons that
       create and listen on a filesystem domain socket. Each new message that
       Courier receives must be acknowledged by every global mail filter.
       Note that if global mail filters are installed, but their daemons are
       not running, Courier will not accept any new messages.

     * Local mail filter

       this filter can be used when the message is addressed to a local
       recipient - when Courier itself will deliver the message to a physical
       mailbox. Local mail filtering is designed to be primarily used by the
       maildrop mail filter. With the local mail filtering installed,
       individual recipients can create files containing mail filtering
       instructions that can selectively accept or reject individual
       messages.

   See courierfilter(8) for more information on global mail filters.

   See maildropfilter(7) for more information on local mail filters.

  Miscellaneous UUCP configuration

   Courier sends UUCP mail by running rmail via uux. The configuration script
   searches for the uux command in the default search path. If your uux
   command is not in a directory that's in your search path you will have to
   modify PATH before running configure.

   Courier receives UUCP mail by expecting your UUCP software to run the
   rmail command, which is installed in /usr/lib/courier/bin. (It's actually
   a soft link to sendmail, but we'll talk about it later). Your UUCP
   software probably does not run commands from this directory by default, so
   you will have to make the necessary adjustments. You can always create
   another soft link in a directory that UUCP searches by default.

Starting and stopping Courier

   To start Courier, run the command /usr/lib/courier/sbin/courier start. To
   stop Courier, run the command /usr/lib/courier/sbin/courier stop. See the
   courier(8) manual page for more information.

   You should add these commands to your system startup and shutdown scripts.

   Note that this command starts and stops Courier's core processes only. It
   does not start any additional daemon processes that you may need, such as
   the mail filtering daemon, the ESMTP server daemon, the POP3 server
   daemon, or the IMAP server daemon.

   The commands courierfilter start, courierfilter stop, esmtpd start, esmtpd
   stop, esmtpd-msa start, esmtpd-msa stop, pop3d start, pop3d stop, imapd
   start, and imapd stop (all commands are installed in the sbin directory)
   are used to start or stop their respective daemons, and they should be
   added to your system startup and shutdown scripts, where required. As
   described in the relevant manual pages, courierfilter should be the first
   daemon process to start, and the last one to terminate. The remaining
   daemons may be started in any order.

Run Courier in parallel to your mail server

   You now have several options for migrating from your existing mail server
   to Courier:

     * Your existing mail server can continue to handle incoming mail, by
       listening on the smtp port. Courier will be used to send all outgoing
       mail. This is accomplished by configuring your mail software to run
       /usr/lib/courier/bin/sendmail to send mail, instead of your current
       sendmail program.
     * Courier can handle incoming mail by listening on the smtp port, and
       your existing mail server can continue to handle all outgoing mail.
       You will need to stop your existing mail server from listening on the
       smtp port, and run the following command:

 /usr/lib/courier/sbin/esmtpd start

       from your system start up script. You should also add
       /usr/lib/courier/sbin/esmtpd stop to your system shutdown script. Note
       that there's a separate script that starts the ESMTP submission server
       on port 587 - /usr/lib/courier/sbin/esmtpd-msa, that is used in an
       analogous fashion.

OPTIONAL: Configure ESMTP authentication and SSL

   Courier supports authenticated ESMTP in order to grant ESMTP relaying
   privileges to remote users. The following steps set up authenticated
   ESMTP:

     * Edit /usr/lib/courier/etc/esmtpd and initialize the ESMTPAUTH
       configuration setting. The configuration file
       /usr/lib/courier/etc/esmtpd-msa is used for the ESMTP submission
       server on port 587. Setting this variable in esmtpd is sufficient,
       because esmtpd-msa merely supplements the settings in esmtpd.
       Explicitly initialize this setting in esmtpd-msa only if you wish to
       apply it to port 587 only.

       ESMTPAUTH is a list of SASL authentication methods to use use.
       Currently, Courier supports LOGIN, PLAIN, CRAM-SHA1 and CRAM-MD5. The
       list of authentication methods is sometimes influenced by the
       installed authentication modules in the Courier Authentication
       Library. Not all authentication modules implement CRAM-MD5/SHA1. The
       authentication modules that support CRAM-MD5/SHA1 authentication are:
       authuserdb, authldap, authmysql, and authpgsql.

     * Your authentication modules may require additional configuration, you
       will have to take care of that too. For example, authpam - the PAM
       authentication module - requires that you also configure your PAM
       library. In this case, you need to configure your PAM library to
       support the "esmtp" service. The PAM library configuration details
       depend on your particular operating system, and are beyond the scope
       of this document. Consult the documentation for your PAM library for
       more information.
     * Restart Courier.

  ESMTP over TLS/SSL

   Courier also supports ESMTP over TLS/SSL, by using the ESMTP STARTTLS
   extension:

     * To implement STARTTLS you will need to install OpenSSL before
       installing Courier. Download OpenSSL from http://www.openssl.org/.
       Follow the instructions provided with OpenSSL to install it. STARTTLS
       has been tested with OpenSSL 0.9.5a.
     * STARTTLS is enabled simply by installing an X.509 certificate as
       /usr/lib/courier/share/esmtpd.pem. If this file exists, the STARTTLS
       ESMTP extension will be automatically advertised. This file must be
       owned by the userid Courier is installed as, and MUST NOT be world
       readable!
     * Note that SSL requires a signed X.509 certificate. You can generate
       your own self-signed certificates with OpenSSL, but mail clients will
       display a warning message the first time they connect to the server.
       To prevent the warning message, you will need to pay money to have
       your certificate signed by a certificate authority. The gory details
       of setting up SSL is beyond the scope of this document, and you should
       consult the OpenSSL documentation for more information.
     * The certificate must be installed as
       /usr/lib/courier/share/esmtpd.pem. This file MUST NOT HAVE any group
       or world permissions! It must be owned by the Courier userid (the
       userid used to install Courier, usually courier or daemon).
     * In times of extreme desperation the script
       /usr/lib/courier/sbin/mkesmtpdcert can be used to generate
       /usr/lib/courier/share/esmtpd.pem. This script will silently terminate
       if OpenSSL is not installed, or if the esmtpd.pem certificate file
       already exists (so it will not be overwritten). This makes it easier
       to have this script invoked from a package install script.
     * Restart Courier's ESMTP server after installing the X.509 certificate.

   Courier will also use TLS/SSL when sending ESMTP mail, automatically. If
   the remote mail server support STARTTLS, Courier will use it
   automatically.

   SSL/TLS settings for the ESMTP client can be adjusted in the
   /usr/lib/courier/etc/courierd configuration file. When sending mail using
   SSL, Courier can optionally verify the remote server's X.509 certificate.
   This is done by setting ESMTP_TLS_VERIFY_DOMAIN to 1, in
   /usr/lib/courier/etc/courierd. Also, TLS_PEERCERTDIR must be set to a
   directory that contains PEM files of X.509 certificates of trusted root
   certificate authorities. The PEM files must be hashed by OpenSSL's
   c_rehash script. When this is done, the remote server's X.509 certificate
   must signed by trusted root CA, else Courier will bounce the recipient.

   Starting with version 0.34, Courier installs a default set of trusted
   public certificate authorities, and the default configuration will require
   the remote server to present an X.509 certificate that's signed by any
   trusted certificate authority. To disable certificate validation, set
   ESMTP_TLS_VERIFY_DOMAIN to 0 in /usr/lib/courier/etc/courierd.
   Alternatively, custom certificates may be installed instead. The
   TLS_TRUSTCERTS setting in /usr/lib/courier/etc/courierd specifies the
   location of trusted certificate authorities.

OPTIONAL: Configure the SECURITY ESMTP extension

   Courier includes an experimental extension to ESMTP that can be used to
   set up secure E-mail delivery between trusted mail relays over an
   untrusted network. This is implemented by an experimental ESMTP extension
   in Courier. Therefore, at present time both the sending and the receiving
   mail relay must be running Courier that's configured to support this
   extension. The specification for this ESMTP extension is publicly
   available. This is a very small extension of the existing, draft-standard
   STARTTLS ESMTP extension. The SECURITY extension should only require minor
   changes to existing mail servers and clients that already implement
   STARTTLS.

  Overview

   The first necessary step is to read the formal definition of the SECURITY
   extension, which can be found on http://www.courier-mta.org. Although the
   following instructions do not use any information directly from this
   document, it is important to understandi how this mechanism works. This
   will be very useful in troubleshooting. This is not called an
   "experimental" extension just for the hell of it.

   The SECURITY extension builds on top of several existing, proven,
   technologies in order to deliver mail with the highest level of security
   that can possibly be implemented using the existing technology. The
   several steps in implementing the SECURITY extension:

    1. Install and configure the STARTTLS ESMTP extension. This extension
       uses TLS/SSL encryption for sending mail.
    2. Create a private, controlled, X.509 Certificate Authority.
    3. Use the private CA to sign X.509 certificates of all mail nodes in the
       trusted mail network. This CA's certificate is also installed in every
       trusted mail node.

   The SECURITY extension is an optional tag that's attached to an E-mail
   message. Courier requires STARTTLS to forward SECURITY-tagged messages,
   and the receiving mail nodes must present an X.509 certificate, signed by
   the private Certificate Authority, before Courier will send the message.
   Courier will refuse to send the message to a mail node that does not
   support STARTTLS, or doesn't present a suitable X.509 certificate.

   Therefore, in an ideal world, mail clients will simply tag messages with
   the SECURITY extension. Obviously, this means that mail clients must be
   updated to implement this feature. Until this happens, Courier will
   provide a workaround that automatically tags all messages for selected
   domains with the SECURITY extension. This is not a perfect solution, and
   it has some minor limitations, which will be mentioned later.

  Install and configure the STARTTLS ESMTP extension

   The first step is to implement ESMTP STARTTLS. Use the instructions
   elsewhere in this document to activate ESMTP STARTTLS support. The
   following instructions use the scripts from OpenSSL 0.9.6, but should also
   work with OpenSSL 0.9.5a.

  Create a private X.509 Certificate Authority

   Create an empty subdirectory:

     mkdir /etc/myca
     cd /etc/myca

   There's a convenient OpenSSL script called CA.pl that you want to copy to
   the current directory:

     cp /usr/share/ssl/misc/CA.pl .

   Your OpenSSL package may have CA.pl installed someplace else. Find it, and
   copy it to /etc/myca. The CA.pl needs to be slightly modified before it
   can be used. Find the following commands in CA.pl, and change them as
   follows:

   Replace:

       system ("$REQ -new -keyout newreq.pem -out newreq.pem $DAYS");

   replace with:

       system ("$REQ -new -nodes -keyout newreq.pem -out newreq.pem $DAYS");

   Also replace:

       system ("$REQ -new -x509 -keyout " .
           "${CATOP}/private/$CAKEY -out ${CATOP}/$CACERT $DAYS");

   replace with:

       system ("$REQ -new -nodes -x509 -keyout " .
           "${CATOP}/private/$CAKEY -out ${CATOP}/$CACERT $DAYS");

   The CA.pl script creates password-protected certificate keys by default.
   Password protected certificates currently do not work with Courier. Adding
   the -nodes parameter turns off password protection. This means that it is
   vital to make sure that the trusted mail relays are properly secured. All
   the encryption in the world will not be of much use if the mail relays are
   running a rootable FTP server (for example). Anyway, run CA.pl to create a
   new certificate authority:

     ./CA.pl -newca

   CA.pl prompts for a basic description of the new CA, then creates the
   certificate and the certificate key. The CA's root certificate is saved in
   /etc/myca/demoCA/cacert.pem.

  Use the private CA to sign X.509 certificates of all trusted mail nodes

   This step must be performed to create the X.509 certificates for every
   mail node in the trusted secure network. First, a certificate request is
   created:

     ./CA.pl -newreq

   CA.pl prompts for a basic description of the new certificate. Special care
   must be paid to the "commonName" setting. "commonName" MUST be set to the
   hostname of the trusted mail node, NOT its mail domain. For example, given
   the following DNS setup for example.com:

      example.com.  MX 10 mx1.example.com.
      example.com.  MX 20 mx2.example.com.

      mx1.example.com. A 192.68.0.1
      mx2.example.com. A 192.68.1.1

   This domain will need two certificates, one with "commonName" set to
   "mx1.example.com", and one with "commonName" set to mx2.example.com.

   Running ./CA.pl produces a certificate request in the file newreq.pem. Run
   the following command to sign it:

     ./CA.pl -signreq

   This step creates the file newcert.pem that contains a new signed
   certificate. The private key from the original certificate request must be
   appended to this file, before the certificate can be used. Simply take the
   newreq.pem file from the previous step, and append the private key in that
   file to newcert.pem. The resulting certificate file should look something
   like this:

    [ description of the certificate ]

 -----BEGIN CERTIFICATE-----

    [ binary goo ]

 -----END CERTIFICATE-----
 -----BEGIN RSA PRIVATE KEY-----

    [ binary goo ]

 -----END RSA PRIVATE KEY-----

   The OpenSSL documentation contains instructions on how to perform the
   equivalent procedure with Diffie-Hellman instead of RSA.

  Configure trusted mail nodes

   Two files must be installed on every trusted mail node.

     * The mail node's certificate, the newcert.pem file from the previous
       step. The following documentation assumes that this file is installed
       as /etc/mycert.pem. This mail node will use this certificate to
       authenticate itself to other trusted mail nodes.
     * The certificate authority file, cacert.pem. The following
       documentation assumes that it's installed as /etc/cacert.pem. The CA's
       certificate is used to authenticate other trusted mail nodes.

   Edit the /usr/lib/courier/etc/esmtpd configuration file. Set TLS_CERTFILE
   to /etc/mycert.pem. Courier will use TLS_CERTFILE to authenticate itself
   to other trusted mail nodes.

   Edit the /usr/lib/courier/etc/courierd configuration file. Set
   TLS_TRUSTSECURITYCERTS to /etc/cacert.pem. Courier will not send ESMTP
   mail tagged with the SECURITY extension to other mail relays unless they
   produce a certificate that's signed by TLS_TRUSTSECURITYCERTS.

  Testing

   The following simple steps can be carried out to verify that everything is
   working correctly. These examples use two mail nodes called
   send.example.com and receive.example.com. The test messages are sent from
   send.example.com, and are addressed to receive.example.com. Courier must
   be restarted on both send and receive, after reconfiguring the machines
   for each test. It is not strictly necessary to do this every time,
   actually, but it's simply easier to do make it a part of the routine. It
   is necessary to restart both the main Courier daemon processes as well as
   the separate ESMTP daemon process (on receive):

     courier stop
     courier start
     esmtpd stop
     esmtpd start

    1. Temporary get rid of /usr/lib/courier/bin/couriertls wrapper on
       receive.example.com. Rename it to couriertls.save. STARTTLS is
       automatically disabled if couriertls is missing,
    2. Run the following command on send.example.com:

     echo "To: postmaster" | /usr/lib/courier/bin/sendmail \
               -S STARTTLS postmaster@receive.example.com

       This message should bounce back since receive has STARTTLS disabled.

    3. Restore couriertls on receive.example.com, but then rename it on
       send.example.com. The situation is now reversed, and the test message
       should still bounce.
    4. Restore couriertls on send.example.com. Edit receive's
       /usr/lib/courier/etc/esmtpd file. Comment out the current TLS_CERTFILE
       setting (which points to the private CA certificate). Reset
       TLS_CERTFILE to /usr/lib/courier/share/esmtpd.pem, which is the
       self-signed test certificate created by the mkesmtpdcert script, when
       STARTTLS support in Courier was first set up.

       Send a test message WITHOUT the "-S STARTTLS" option. This message
       should go through, assuming all the other setting in all configuration
       files are the initial defaults. The regular ESMTP STARTTLS extension,
       without authentication, will be used the deliver this message. Verify
       this by checking the headers in the received message on
       receive.example.com.

       Send a test message WITH the "-S STARTTLS" option. It should bounce,
       even though receive.example.com supports STARTTLS. That's because it
       is using an X.509 certificate that's not signed by the private CA
       authority.

    5. Restore TLS_CERTFILE on receive, and send a test message with the -S
       STARTTLS option, which should now go through.

  Force SECURITY for selected domains

   As demonstrated by the test messages, messages must be tagged with the
   SECURITY extension in order for them to be securely transmitted. This must
   be done by the sending mail client. Until mail clients support SECURITY
   Courier can automatically add the SECURITY tag to every message addressed
   to a domain. This is done by entering the domain in the esmtproutes
   configuration file using the following syntax:

 receive.example.com:  /SECURITY=STARTTLS

   Repeat the tests in the previous section, but this time add and delete
   this entry in /usr/lib/courier/etc/esmtproutes instead of using the -S
   STARTTLS option. The test messages must still bounce or not bounce in the
   same way.

   Consult the courier(8) manual page for more information on the esmtproutes
   configuration file.

  Limitations

   This setup makes it virtually impossible to intercept mail traffic between
   trusted mail nodes. Even if the DNS cache is poisoned to intercept mail to
   a hostile mail node, mail will not go through since the attacker will not
   have a signed X.509 cert. However, all is lost if the mail nodes
   themselves are compromised directly. After securing the compromised node,
   everything must be rebuilt. A new CA must be created, and all mail nodes
   must now receive new certificates. Once support for certificate revocation
   lists is improved, this situation will get somewhat better.

   Another possible way to mitigate that possibility is to use a different
   certificate authority for every trusted mail node. TLS_TRUSTSECURITYCERTS
   can point to a directory, instead of a file. This directory can contain
   multiple certificate authorities (hashed by OpenSSL's c_rehash script).
   Then, only the compromised mail node's authority certificate needs to be
   tossed out, regenerated, and redistributed.

   TODO: it may be possible to avoid generating individual certificates, and
   distribute self-signed certificate authority certs only, with a
   properly-initialized commonName field. This needs to be researched.

   There are some minor differences between using -S STARTTLS versus putting
   the domain into esmtproutes. If the sending mail node forward mail to this
   domain via UUCP, -S STARTTLS will bounce. Since esmtproutes does not apply
   to UUCP, putting this domain in esmtproutes will have no effect
   whatsoever.

OPTIONAL: Configure the Sender Policy Framework

   Courier can optionally check the return address on all SMTP mail for the
   sender's published Sender Policy Framework (SPF). Keep in mind SPF is an
   experimental protocol that's still maturing. Courier's SPF configuration
   is set up in the "bofh" configuration file, and is fully explained in the
   courier(8) manual page.

OPTIONAL: Configure the IMAP server

   Courier includes an integrated IMAP server. The following steps set it up:

     * Edit /usr/lib/courier/etc/imapd. If you want to use IMAP SASL
       authentication, set up the IMAP_CAPABILITY variable. It performs the
       equivalent function as the ESMTPAUTH variable in the esmtpd
       configuration file, except that IMAP_CAPABILITY also sets several
       other IMAP capabilities that are advertised to IMAP clients. Also, for
       IMAP, CRAM-MD5/SHA1 authentication has been tested, and is known to
       work, so it is listed as a default. Also, note than if the authpam
       authentication module is used, you will need to configure the "imap"
       PAM service. Other authentication modules have their own requirements
       too.
     * Uninstall any existing IMAP server that you have, remove the entry for
       the IMAP port in /etc/inetd.conf, and restart the inetd daemon.
     * Add the following command to your system startup script

 /usr/lib/courier/sbin/imapd start

       Of course, add /usr/lib/courier/sbin/imapd stop to your shutdown
       script too.

   NOTE: if you have previously installed the stand-alone version of the
   Courier-IMAP server, you will need to remove it prior to using the
   directly integrated version. They use the same base source code, but have
   a slightly different configuration.

   NOTE: this IMAP server supports maildirs only. It does not support mbox
   file mailboxes.

  Foreign character set sorting/searching

   The IMAP server can sort and search messages using other than the default
   us-ascii/iso-8859-1 character set. You can find the list of available
   character sets in the file unicode/charsetlist.txt.

   The default configuration includes only the ISO-8859-1/US-ASCII character
   set. Use the --enable-unicode option to include all character sets.

   If the configure scripts finds that GnuPG 1.0.5 is installed, the
   configure script will also add the utf-8 character set to the default
   setting.

   It is also possible to include translation tables only for selected
   character sets. Example:

   --enable-unicode=iso-8859-1,utf-8,iso-8859-10

   Technically, IMAP servers must support the UTF-8 character set, however
   few IMAP clients (I've yet to see one, actually) care about UTF-8, so the
   UTF-8 character set is optional in Courier-IMAP. The only required
   character set - which is always included, explicitly or implicitly - is
   ISO-8859-1/US-ASCII.

   The utf-8 character set MUST be included if GnuPG 1.0.5 is installed (see
   "Configure encryption for the webmail server" for more information).

   Note that character set translation tables take up additional memory. This
   should not be a problem in most cases. Most compilers place the read-only
   character set tables into a shared text segment, which is shared by all
   running server instances. Using --enable-unicode should not really be much
   of a burden for most modern operating systems.

   Attentive individuals will observe that all character set tables are
   compiled even without the --enable-unicode option. That is normal -- only
   the explicitly selected character set tables will actually make it into
   the final executable.

Configure IMAP shared folders

   It is possible to share folders between different mailboxes, via IMAP. See
   the file maildir/README.sharedfolders.(txt|html) for more information.

OPTIONAL: Configure IMAP over SSL

   To implement IMAP over SSL you will need to separately obtain and install
   OpenSSL. Download OpenSSL from http://www.openssl.org/. Follow the
   instructions in the OpenSSL package to install it and configure it. IMAP
   over SSL has been tested with OpenSSL 0.9.5a.

   The /usr/lib/courier/etc/imapd-ssl configuration file sets some additional
   options for OpenSSL, which you may need to adjust. Consult that
   configuration file for additional information. Then, you also have to run
   the /usr/lib/courier/sbin/imapd-ssl script from your system startup and
   shutdown scripts, just like the /usr/lib/courier/sbin/imapd script. You
   may accept both SSL and non-SSL connections by running both scripts.

   Note that SSL requires a valid, signed, X.509 certificate to be installed
   where Courier expects to find it. The default location for the X.509
   certificate, in PEM format, is /usr/lib/courier/share/imapd.pem. The X.509
   certificate must be signed by a certificate authority that is known to the
   IMAP client. You can generate your own self-signed certificate by running
   the script /usr/lib/courier/share/mkimapdcert which will work too, except
   that IMAP clients using SSL will display a warning message the first time
   they connect to the server. To get rid of the warning message you'll have
   to pay for a signed X.509 certificate. The gory details of setting up SSL
   is beyond the scope of this document, and you should consult the OpenSSL
   documentation for more information.

   The mkimapdcert script will not overwrite an existing imapd.pem
   certificate, in order to allow precompiled packages to simply call
   mkimapdcert after installation, without worry.

   The IMAP server also supports the IMAP STARTTLS extension as an
   alternative or a complement to IMAP over SSL. The
   /usr/lib/courier/etc/imapd-ssl configuration file is also used to enable
   or disable IMAP STARTTLS, which has all the same requirements and
   prerequisites as IMAP over SSL.

OPTIONAL: Sending mail via an imap connection

   This server allows using the IMAP connection to send E-mail. Normally, the
   IMAP protocol provides only access to mail in an existing mail account,
   and mail clients must use SMTP in order to send mail. The Courier-IMAP
   server has an optional setting to enable mail to be send via an IMAP
   connection in a manner that should work with all existing IMAP mail
   clients. This can be useful when an account is logged in from a shared
   access pool which normally blocks most access to the SMTP port.

   This is implemented by enabling a setting in the imapd configuration file
   that designates a folder as a special "Outbox" folder. The default setting
   is a folder called "Outbox" (IMAP path INBOX.Outbox), but the name can be
   changed to anything. This folder, for the most part, is no different than
   any other folder. If a folder by that name doesn't exist, it needs to be
   created, just like any other IMAP folder. It looks and acts like any other
   folder, except that each message added to the folder, via IMAP's APPEND or
   COPY command, will also be mailed out by the Courier-IMAP server to the
   addresses listed in the To:, Cc:, and Bcc: headers.

   It should be possible to use this to send mail from any IMAP client by:

    1. Composing a draft message, telling the IMAP client to save the draft
       message in its drafts folder on the IMAP server.
    2. Opening the drafts folder, and moving or copying the message to the
       Outbox folder.
    3. The act of copying the message into the Outbox folder will send the
       mail. There won't be any explicit notification to the fact that the
       message was sent, so it's a good idea to include your own E-mail
       address on the Cc: list.

     NOTE: it is tempting to configure the IMAP mail client to use Outbox as
     its default folder for saving drafts. Resist the temptation. If you
     forget, you'll save a partially completed draft, which will be then
     obediently mailed out.

     NOTE: the message, in addition to being sent, will be saved in the
     folder in the normal fashion. After saving the message, reopen the
     Outbox folder and delete the sent message, or move it someplace else.

     NOTE: when enabled, the Courier-IMAP server will advertize a private
     XCOURIEROUTBOX IMAP capability. It is theoretically possible to code an
     IMAP mail client that reads this capability and automatically configures
     itself accordingly -- when this IMAP capability is present -- to send
     E-mail in the normal way but using the IMAP connection. At this time,
     I'm not aware of any actual mail clients that know how to do this.

     NOTE: many mail clients save some additional internal information in
     headers of draft messages. The internal information is normally removed
     before the mail client sends the message. Make sure that none of this
     extra information is something that should not be mailed out.

OPTIONAL: Configure IMAP realtime folder status updates

   If the FAM, the File Alteration Monitor (http://oss.sgi.com/projects/fam/)
   is installed it will be possible to allow multiple clients to open the
   same folder, and have all clients to be simultaneously notified of any
   changes to the folder contents.

   After installing the server see the imapd(8) manual page for more
   information.

OPTIONAL: Configure SMAP

   Starting with Courier 0.43, the IMAP server supports an experimental mail
   access protocol, dubbed "Simple Mail Access Protocol". SMAP is an
   experiment to provide enhanced mail processing beyond what's currently
   possible with IMAP. SMAP's purpose is to prototype and develop advanced
   mail access functionality that's not possible with IMAP. SMAP is disabled
   by default. Uncomment the SMAP_CAPABILITY setting in the imapd
   configuration file in order to enable SMAP. The Cone mail client supports
   SMAP.

OPTIONAL: Configure the POP3 server

   Courier includes an integrated POP3 server. The following steps will set
   it up:

     * Edit /usr/lib/courier/etc/pop3d. Very few POP3 clients support POP3
       SASL authentication, but if you want to use it, for some reason,
       uncomment the POP3AUTH variable. It performs the equivalent function
       as the corresponding variable in the esmtpd and imapd configuration
       files. For POP3, SASL LOGIN authentication has been tested, and is
       known to work, and CRAM-MD5/SHA1 has not been tested. Also, note than
       if authpam is used, you will need to configure the "pop3" PAM service.
       Other authentication modules have their own requirements.
     * Uninstall any existing POP3 server that you have, remove the entry for
       the POP3 port in /etc/inetd.conf, and restart the inetd daemon.
     * Add the following command to your system startup script:

 /usr/lib/courier/sbin/pop3d start

       Of course, add /usr/lib/courier/sbin/pop3d stop to your shutdown
       script too.

   NOTE: this POP3 server supports maildirs only. It does not support mbox
   file mailboxes.

OPTIONAL: Configure POP3 over SSL

   Implementing POP3 over SSL is very similar to implementing IMAP over SSL.
   The only differences are that the startup/shutdown command is
   "/usr/lib/courier/sbin/pop3d start" and "/usr/lib/courier/sbin/pop3d
   stop", the configuration file is /usr/lib/courier/etc/pop3d, the name of
   the required SSL certificate is /usr/lib/courier/share/pop3d.pem, and the
   command to generate a test SSL certificate is mkpop3dcert.

OPTIONAL: Configure the IMAP/POP3 aggregator proxy

   It is possible to distribute IMAP and POP3 mailboxes between multiple
   server.

   See imap/README.proxy for more information.

OPTIONAL: Configure the webmail server

   The integrated webmail server is made up of two parts. The first part, by
   default, is installed as /usr/lib/courier/libexec/courier/webmail. You can
   simply copy this binary executable to your web server's cgi-bin directory,
   or create a link from the cgi-bin directory to this program. This is a
   small stub program that connects, via a local socket, to the sqwebmaild
   daemon process, which implements the webmail service. It is necessary to
   start the webmail server by adding the following command to the system
   startup screen (so that the webmail server gets automatically started at
   boot):

   /usr/lib/courier/sbin/webmaild start

   (It is also possible to run "webmaild stop" from the system shutdown
   script in order to shut down webmail service gracefully).

   Note that the webmail server is used to access mail in existing accounts
   only. There is no provision to create accounts through the webmail
   interface (nor there should be).

   Your web server also needs to be configured to use HTTP/1.0 when talking
   to any MSIE browser. The MSIE browser has a number of bugs in its HTTP/1.1
   implementation, at least as of MSIE 4.x and 5.x. You must configure your
   web server to use HTTP/1.0 when talking to any MSIE browser (at least
   until MSIE gets fixed). The problem has to do with downloading
   attachments. Apparently, MSIE forgets how MIME works, when it uses
   HTTP/1.1. For the Apache server, insert the following directive in
   httpd.conf:

 BrowserMatch "MSIE" nokeepalive downgrade-1.0 force-response-1.0

   Recent versions of Apache already have a similar directive for a specific
   version of MSIE, MSIE 4.0b2. Just replace it with a browsermatch for any
   MSIE version.

  SELinux

   The following extension may be necessary to make webmail work when SELinux
   kernel extensions are turned on:

 allow httpd_sys_script_t var_t:sock_file write;
 allow httpd_sys_script_t unconfined_t:unix_stream_socket connectto;

  Modified UTF-7 encoding and unicode support

   Most IMAP clients use a Unicode-based encoding method called "modified
   UTF7" in order to represent names of folders that contain 8-bit
   characters. If there will not be any IMAP access to the mail accounts in
   question, there's no need to include all this baggage. The option
   --disable-utf7-folder-encoding to the configure script will turn this off.

   There are a few IMAP clients that do not use modified UTF7 to encode
   folder names. The option --disable-utf7-folder-encoding can be used if
   that is the case. It is currently not possible to support both UTF7 and
   non-UTF7 clients at the same time.

   By default, the configure script works like this. It takes the character
   set used for the HTML templates, and loads the Unicode mappings just for
   that character set. By default, Courier's webmail server is distributed
   with a default set of HTML templates that use the iso-8859-1 character
   set. If you are installing a modified derivative that includes additional
   templates, the configure script will pick up any additional character sets
   used by those templates.

   Sometimes it is useful to include additional unicode tables. The list of
   available unicode tables can be found in unicode/charsetlist.txt. This is
   useful when there are alternative encodings for the same base character
   set, like KOI8-R and IBM866. The option "--enable-unicode=koi8-r,ibm866",
   when used with koi8-r HTML templates, will allow the webmail server to
   display ibm866-encoded E-mail using the koi8-r character set (and vice
   versa). Note, for this to work you will need to install a set of KOI8-R
   HTML templates. In a pinch, you can simply edit webmail/html/en/CHARSET.

  Spell checking

   The webmail server can use either the ispell or the aspell package for
   spell checking. Install ispell or aspell before installing Courier.

   NOTE: Courier assumes that the spell checking dictionary is called
   "english". Some systems use a different name for the default spell
   checking dictionary. To change the name of the spell checking dictionary
   used by the webmail server, put the name of the dictionary into the file
   /usr/lib/courier/share/sqwebmail/html/en-us/ISPELLDICT.

  Images

   It is also necessary to install the static icon images used by the webmail
   server. The installation script copies the static images to the
   /usr/lib/courier/share/sqwebmail/images directory. By default, the webmail
   server uses the URL "/webmail/" to specify the location of the static
   images, for example: /webmail/folders.gif. This means that you must create
   a subdirectory called "webmail" in your web server's document root -
   typically /usr/local/etc/apache/htdocs/webmail, or
   /usr/local/www/htdocs/webmail, or something similar. You will need to
   determine the actual location of your web root directory, which varies
   from system to system. Then, create a subdirectory named "webmail", and
   copy all the icons to that directory.

   Another possibility is to install a soft link, instead of creating the
   webmail sub directory, and point the soft link to
   /usr/lib/courier/share/sqwebmail/images (you also must make sure that the
   web server is configured to follow symlinks).

   There is a configuration option, --enable-imageurl, that can be used to
   use something other than /webmail/ as the URL prefix for images.

  Alternative timezones

   The file /usr/lib/courier/share/sqwebmail/html/en-us/TIMEZONELIST contains
   a list of alternative timezones. By default all dates and times are shown
   in the server's default timezone, and the dropdown list on the login
   screen can be used to select an alternative timezone. The default
   alternative timezone list that lists only a small number of timezones.
   Additional timezones can be entered into this file to be shown on the
   login web page.

  LDAP address book import

   The webmail server can import E-mail addresses from public LDAP address
   books into an individual address book. A default systemwide list of
   accessible LDAP address books is defined for everyone, and individuals can
   configure additional LDAP address books for themselves.

   OpenLDAP runtime libraries and tools are required to be installed in order
   to search LDAP address books. It is not necessary to have OpenLDAP
   development libraries installed. The webmail server simply runs the
   ldapsearch tool to query LDAP address books, and parses the results.

   The default list of systemwide-accessible LDAP address book is defined in
   the ldapaddressbook configuration file. See courier(8) for more
   information.

   The webmail server runs /usr/lib/courier/share/sqwebmail/ldapsearch to
   search an external LDAP address book. This is a wrapper shell script that
   calls OpenLDAP's ldapsearch tool. The configuration script attempts to
   find the location of where OpenLDAP tools are installed. The path to
   ldapsearch in this shell script should be verified and fixed, if
   necessary. The default shell script adds some additional options to
   ldapsearch to limit the search time to sixty seconds, and to return a
   maximum of twenty entries from the address book.

OPTIONAL: Configure webmail calendaring

   Optional calendaring services can be enabled in the webmail server. Right
   now, the current implementation provides basic calendaring services. For
   more information on calendaring, see the file pcp/README.html.

  Webmail session timeouts

   A login session is automatically logged out after certain period of
   inactivity. The timeout period defaults to 20 minutes, and is set by the
   --enable-softtimeout option to the configure script. It is also possible
   to adjust this value by setting the SQWEBMAIL_TIMEOUTSOFT environment
   variable. For example, with Apache, by adding the following to httpd.conf:

 SetEnv SQWEBMAIL_TIMEOUTSOFT 3600

   There is also a hard timeout, which logs out a session no matter what. The
   default of two hours is changed with the --enable-hardtimeout option to
   the configure script, and the SQWEBMAIL_TIMEOUTHARD environment variable.

   WARNING:

   The hard timeout interval is used to calculate the maintenance of the
   login cache (if that option is selected). This factor is used in the
   cleancache.pl cleanup script, and changes to this value must be
   coordinated appropriately. It is not possible to use different hard
   timeout values with the same login cache (in different virtual domains, as
   described in the next session). Leisurely tinkering with this environment
   variable is STRONGLY DISCOURAGED, it's very easy to screw up the whole
   system. You've been warned.

   If you adjust the hard timeout, you must simultaneously delete your
   current login cache directory, and adjust $timeouthard in the installed
   cleancache.pl script.

  Domain-based templates

   The default set of templates for the dynamically generated HTML is
   installed in /usr/local/share/sqwebmail/html. When the same server is used
   to provide webmail access for multiple domains it is possible to specify a
   different set of HTML templates for each domain.

   This functionality is not directly implemented in SqWebMail, simply
   because there is no standard way to specify this. Instead, this is
   something that will need some minor work set up.

   Domain-based templates are implemented by making the web server set the
   environment variables SQWEBMAIL_TEMPLATEDIR prior to running the sqwebmail
   binary. The contents of this environment variable override the default
   location of /usr/local/share/sqwebmail/html. By having the web server
   initialize this variable based on the domain name it is possible to
   present different templates, based on the domain name used.

   To do this, make copies of the HTML template directory,
   /usr/local/share/sqwebmail/html. Then, configure the web server to
   initialize SQWEBMAIL_TEMPLATEDIR appropriately. For example, with Apache:

   <VirtualHost a.b.c.d>
     ServerName webmail.example.com
     [...]
     SetEnv SQWEBMAIL_TEMPLATEDIR /usr/local/share/webmail/webmail.example.com
     [...]
   </VirtualHost>

   The possibilities are endless.

  Name-based templates

   It is now possible to display two or more templates from the same CGI
   binary WITHOUT setting up multiple domain names.

   For example, with Name-based templates an sqwebmail administrator can set
   up sqwebmail to display a template in the /usr/local/share/sqwebmail/html
   directory when sqwebmail is called from the URL:
   http://www.foo.com/cgi-bin/sqwebmail

   And display a different template in the
   /usr/local/share/sqwebmail/alternate-html directory when sqwebmail is
   called from the URL: http://www.foo.com/cgi-bin/sqwebmail-alt-template

   This is made possible by a little web server magic (explained below in the
   section entitled "Apache Name-based template configuration example") and
   the setting of TWO sqwebmail environment variables:

 SQWEBMAIL_TEMPLATEDIR
 SQWEBMAIL_IMAGEURL

   You should recognize the SQWEBMAIL_TEMPLATEDIR environment variable from
   the section above on Domain-based templates. If you haven't read that
   section yet, please do so now.

   The SQWEBMAIL_IMAGEURL environment variable is new in versions of
   sqwebmail greater than sqwebmail-3.5.3.20030629. It allows us to set, at
   run time, the image URL, or the root URL, in which to look for our
   template's images. This image URL is then automatically inserted into the
   current template anytime a conditional image tag or an IMAGEURL tag is
   encountered.

   This is an example of a conditional image tag:

   [#@image.gif, ... @text@#]

   The conditional image tag is replaced at template processing time with an
   HTML <img src="..."> tag if (hence the word "conditional") sqwebmail is
   set up to display images.

   This is an example of an IMAGEURL tag:

   [#IMAGEURL#]

   The IMAGEURL tag is replaced at template processing time with the contents
   of the SQWEBMAIL_IMAGEURL environment variable, if set, and otherwise with
   the value of the --with-imageurl configure option, which defaults to
   "/webmail".

  Apache Name-based template configuration example

   Let's take a look at a simple Apache Name-based sqwebmail template
   configuration example:

  
   # Sqwebmail Alternate Template URL
   ScriptAlias /cgi-bin/sqwebmail-alt-template "/usr/local/apache/cgi-bin/sqwebmail"

   <Location /cgi-bin/sqwebmail-alt-template>
       Setenv SQWEBMAIL_TEMPLATEDIR "/usr/local/share/sqwebmail/alternate-template"
       Setenv SQWEBMAIL_IMAGEURL "/alternate-webmail"
       [...]
   </Location>
      

   The above should allow your users to run sqwebmail with the template in
   /usr/local/share/sqwebmail/alternate-template and an image URL of
   /alternate-webmail, simply by calling sqwebmail from the following URL:

   http://www.yourdomain.com/cgi-bin/sqwebmail-alt-template

   The original sqwebmail templates would then still be available from this
   URL:

   http://www.yourdomain.com/cgi-bin/sqwebmail

   Using Apache's <Location> directive we can utilize a virtually unlimited
   number of templates without setting up a single virtual domain.

OPTIONAL: Configure mail filtering for the webmail server

   This is an optional feature where the webmail server is used to
   automatically set up mail filtering rules to forward or deliver incoming
   mail to folders. This feature requires maildrop to be used as the local
   mail delivery agent.

   Edit the courierd configuration file, and follow the instructions in that
   file to install maildrop as the local mail delivery agent. Then, follow
   the instruction below to create the maildirfilter configuration file,
   which may be installed either in the global configuration file directory
   (/usr/lib/courier/etc by default), or in each individual Maildir (which
   overrides the global default).

   Implementing mail filtering requires a couple of dominos to fall in the
   right order. This is not difficult to do, but is a bit tricky. Here's how
   it works, in general. Specifics follow.

   Some people would probably have a difficult time setting it up. That's to
   be expected. The implementation allows only selected accounts to be set up
   for mail filtering, so the suggested way is to attempt to set up mail
   filtering for one account only, test it to make sure it works, then roll
   it out globally.

  The big picture

   The maildrop mail filter is used to do the actual mail filtering. maildrop
   must be installed as your local mail delivery agent. The next thing to do
   is to actually learn how maildrop works, and learn its filtering language.
   Although the mail filter will be automaticaly generated here, you still
   need to become familiar with the filtering language in order to
   troubleshoot any installation problems. maildrop comes with manual pages
   documenting the filtering language, as well as some examples. Read them.

  The little picture

   Here's what's going to happen. The webmail server will automatically
   generate a maildrop filtering recipe. maildrop reads the recipe, and does
   its thing. Sounds simple enough, right?

   Well, it's not. There are a few little details that need to be resolved.

   For starters, the default maildrop filtering recipe is $HOME/.mailfilter.
   That's how things usually work physical system accounts are used. When
   virtual mailboxes are installed, things are less murky. There are several
   ways to set up virtual mailboxes, described elsewhere in this INSTALL
   file, so the actual implementation varies from system to system. Somehow,
   the virtual mailboxes share the same physical account, and have the same
   $HOME. In that case the usual approach is for each virtual mailbox to have
   the corresponding mail filtering recipe manually specified to maildrop as
   an extra command line argument. Review the maildrop documentation for more
   information.

   Now, on the other hand, the webmail server doesn't really know anything
   about physical and virtual accounts. The mapping between a login ID and
   the maildir is completely encapsulated in the black box-type
   authentication library. The login ID and password are validated by the
   authentication library, which obtains the maildir corresponding to the
   login ID, and the webmail server is started for that maildir. Whether or
   not a login ID corresponds to an actual system account or to virtual
   account, that's something the webmail server doesn't really know, or care.
   All it cares about is the maildir where all the mail is, and that's the
   end of the story. (The IMAP and POP3 servers work the same way).

   So, the issue is that the webmail server needs to find the corresponding
   maildrop filtering recipe, so it knows where to write the mail delivery
   instructions. That's the deal

   In order for mail filtering to be enabled, it is necessary to initialize
   the file named maildirfilterconfig in the maildir itself. This is where
   the webmail server runs, so it simply reads this file. The contents of
   this file should be as follows:

 MAILDIRFILTER=pathtomailfilter
 MAILDIR=pathtomaildir

   pathtomailfilter specifies the location of the maildrop filtering recipe
   for this maildir, relative to the maildir itself. Set the current
   directory to the maildir directory. Now ask yourself, where's my maildrop
   filtering recipe?

   In most cases, where virtual mailboxes are not used, everyone's maildir is
   $HOME/Maildir, and maildrop uses $HOME/.mailfilter by default. In this
   case, pathtomailfilter must be set to ../.mailfilter.

   When virtual mail accounts are used, this will obviously be something
   else. The only requirement is that the maildrop filtering recipe and the
   maildir must be on the same filesystem or partition.

   pathtomaildir is the other half of the story. When maildrop gets a message
   to deliver, maildrop needs to know where the mailboxes and folders are.
   Maildrop begins running in what it considers to be the recipient's home
   directory, reading either .mailfilter, by default, or the file specified
   on the command line.

   The webmail server needs to generate filtering instruction that deliver
   messages to its maildir. By default, the maildir for non-virtual accounts
   is $HOME/Maildir, so pathtomaildir needs to be set to ./Maildir.

  Summary for virtual accounts

   Basically, 99% of the time MAILDIRFILTER will be ../.mailfilter and
   MAILDIR will be ./Maildir. When virtual mail accounts are used, maildrop
   still must be used as a mail delivery agent. Somehow, the correct maildir
   that corresponds to the recipient's mail account must be specified as the
   argument to maildrop. Usually all or most virtual accounts are set up
   inside a single physical account. In that case it is necessary to set up a
   different maildrop filtering recipe file for each virtual mail account
   (since everyone's $HOME/.mailfilter will be the same file), and in each
   maildir specify the relative path to its corresponding filtering recipe,
   and the relative path to the maildir from the default home directory.
   Then, for each virtual mail account, the mail server must run maildrop to
   do the actual mail delivery, explicitly specifying the filtering recipe to
   be used.

  The global maildirfilterconfig file

   In most cases where virtual mail accounts are not used, every maildir's
   maildirfilterconfig should be the same. As an alternative to installing
   the same maildirfilterconfig in each maildir, it is possible to install a
   single maildirfilterconfig systemwide.

   Install the global maildirfilterconfig in Courier's configuration
   directory (/usr/lib/courier/etc by default).

   The global maildirfilterconfig will be used unless maildirfilterconfig
   exists in the maildir directory. Therefore, the global maildirfilterconfig
   can be used to provide a default for the majority of the mail accounts,
   and any exceptions are handled by installing maildirfilterconfig in the
   maildir directory, whose contents will override the global file.

  Happy filtering.

   If everything is set up correctly, the webmail menu will present a new
   link to a screen where mail filtering rules are defined and installed. A
   mail filter consists of a condition, and an action. A condition is usually
   based on the contents of some header, or the message body. Regular
   expressions are allowed. Which means that certain special characters must
   be quoted. For example, to search for the string "[announce]" verbatim in
   the subject header, it must be entered as "\[announce\]". Pattern
   matching, for now, is case-insensitive. The regular expression syntax uses
   pretty much the same syntax as Perl. See the maildropfilter manual page
   for more information.

   Multiple mail filtering rules can be installed. Their relative order can
   be rearranged by selecting a filtering rule, then selecting either the
   "Up" or the "Down" button. It is necessary to select "Save all changes"
   for any changes to the filtering rules to take effect. Leaving that page
   in any other way will throw away all changes made.

  Webmail runtime configuration

   There are some options which can be used to change the webmail server's
   behavior for individual accounts, or globally, using the "Account Options"
   feature in the Courier Authentication library. The individual account's
   setting takes precedence over the DEFAULTOPTIONS settings in the
   authdaemonrc configuration, so for example if you want to disable webmail
   access for most accounts but enable it for a select few, you can set
   DEFAULTOPTIONS="disablewebmail=1" in the authdaemonrc configuration file,
   and add the option disablewebmail=0 to individual accounts. See the
   section "Account options" in README_authlib.html in the courier-authlib
   package for more information on setting the following account options:

   disablewebmail - if set to a non-zero value, this account will not be
   permitted to login to webmail (e.g. because the user is only allowed to
   use POP3 or IMAP)

   wbnochangingfrom - if set to a non-zero value, the webmail server will not
   allow the From: header to be changed, it will always have its default
   value.

   wbnochangepass - if set to a non-zero value, the webmail server will not
   allow passwords to be changed. See "Changing mail account passwords using
   the webmail server", below, for more information.

   wbusexsender - if set to a non-zero value, the webmail server will attach
   an X-Sender: header to all outgoing messages. This can be used in the
   event you would like to be able to modify the From: header, yet also be
   able to track sent mail to the original account.

   wbnoimages - if set to a non-zero value then no images or icons will be
   used. The generated interface will be a text-only interface.

   wbnodsn - set to a non-zero value then the option to request delivery
   confirmation receipts will not be shown.

OPTIONAL: Changing mail account passwords using the webmail server

   After installing the webmail server be sure to test that the login
   password can be changed through the webmail server.

   If you do not want to use the password change function you can also remove
   the sqwebpasswd program. This is a helper program, installed with the
   set-groupid bit set, that relays the password change request to the
   authentication daemon, through the filesystem socket that is not globally
   accessible. The password change request consists of the account name, the
   old password, and the new password. The password change request is
   validated by the authentication daemon, and the old password must match
   the existing password on the account, before the password change goes
   through. This set-groupid helper program is safe to use.

OPTIONAL: Configure autoreplies for the webmail server

   Enabling mail filtering, according to the instructions in the previous
   section, automatically enables MIME autoreply capability. The webmail
   interface can be used to configure simple autoresponders. By default there
   is no limit on the number of the size of created autoreplies, therefore it
   is recommended that a quota be set up on the autoreplies.

   An global autoreply quota is set up by initializing the
   /usr/lib/courier/etc/autoresponsesquota configuration file. This file sets
   the autoreply quota globally. An autoresponsesquota file in the Maildir
   will override the global quota setting for that maildir only. See the
   courier(8) manual page for the description of the autoresponsesquota file.

   Autoreplies can include any valid MIME content (MIME content other than
   plain text can be uploaded). The following special procedure needs to be
   used to prepare multipart autoreply content, such as text and html
   alternatives of the same message:

   Assign a filename extension to the message/rfc822 MIME content. For
   example, edit your mime.types file, find the message/rfc822 MIME type
   (append one if it's not in mime.types), and make sure that it has at least
   one filename extension, such as "msg".

   Prepare the multipart MIME autoreply. The most convenient way is to
   prepare a normal E-mail message using a conventional E-mail client. Save
   the RFC822-formatted message in a file with a ".msg" extension, and upload
   it on the autoreply screen.

   Webmail handles uploaded message/rfc822 content by removing all headers
   except the MIME headers, leaving the MIME content type header, and the
   actual MIME content.

   Normally there is no limit on the number or the total size of autoreplies
   configured via the webmail server. A quota can be installed by
   initializing the autoresponsesquota configuration file. See courier(8) for
   more information.

OPTIONAL: Configure encryption for the webmail server

   This is an optional feature in the webmail server that uses GnuPG to send
   and receive encrypted/signed E-mail. There is no encryption code in the
   webmail server, it uses GnuPG to do encryption and decryption. For more
   information on setting up and using encryption, read the file
   gpglib/README.html in the source distribution.

OPTIONAL: Quota support

   There are two ways to implement a quota on the size of a mail account:
   filesystem quotas and maildir quotas:

  Filesystem quotas

   The maximum disk space quota is implemented within the operating system's
   filesystem support code. Here, the operating system enforces the maximum
   disk space that can be used by each account. This is the only reliable
   quota implementation if individual accounts have login access to the mail
   account. Maildir quotas (see below) are implemented entirely within the
   maildir support code, and can easily be superceeded by anyone with login
   access to the mail account. Additionally, mail accounts must all be system
   accounts. Virtual accounts -- that share the same physical system userid
   -- cannot usually be support by filesystem-based quotas, because all mail
   accounts have the same userid and groupid.

   The webmail server cannot be used with filesystem quotas. The webmail
   server creates and maintains, all by itself, a number of database files
   that are used to quickly index and access messages. If an account exceeds
   its disk quota, the webmail server will not be able to create and update
   those database file, which results in a rather spectacular crash. If login
   access is available, it is possible to log in and manually delete some
   files to reclaim some disk space. If login access is not available, the
   administrator will have to manually fix the account -- the webmail server
   will not even be able to open an existing folder and delete messages in
   order to free up disk space. There is some good news, though: the IMAP and
   the POP3 server can still be used to access and delete messages from the
   mail account. Due to the way that out-of-quota condition is handled by the
   IMAP server, some IMAP clients may mark any existing messages in the
   account as unread, but that is a minor glitch that does no harm.

  Maildir quotas

   Courier can manually enforce a quota for mail accounts that use maildirs.
   This quota enforcement is implemented entirely in software, and is
   available only when maildirs are used. This quota implementation will also
   work with virtual accounts. Maildir quota support is available only with
   userdb, LDAP, MySQL and PostgreSQL authentication back-ends. Maildir
   quotas are supported by IMAP, POP3, and the webmail server. To add a
   maildir quota with userdb, run the following commands, for example:

 userdb account set quota=quota
 makeuserdb

   Here, account identifies the account to which the quota applies, and quota
   is the quota specification, as described in the maildirquota(7) manual
   page.

   To implement a quota with an LDAP, MySQL, or a PostgreSQL back end, simply
   follow the instructions given in the corresponding configuration file.

Account OPTIONS

   It is possible to adjust certain parameters on an account-by-account
   basis. This feature is actually implemented in the Courier Authentication
   Library. See ACCOUNT OPTIONSin the auth_generic manual page.

OPTIONAL: Configure outbound faxing

   Fax sending is disabled by default and must be explicitly enabled,
   according to the following instructions. After fax sending is enabled,
   addressing an E-mail message to <5552000@fax> will have this message
   faxed.

   Of course, the necessary hardware and software must be available. The
   requisite hardware is a class 2 faxmodem attached to a serial port.
   Additional software, separate from Courier, must also be installed.
   Courier does not handle the actual job of faxing. Courier only reformats
   E-mail messages as fax images, and runs mgetty+sendfax to send the fax.
   Courier also needs additional software to convert E-mail messages to
   faxes. All additional software must be separately installed, configured,
   and tested before enabling faxing in Courier. Most systems already include
   the following software as part of the base operating system, so in most
   cases adding fax support will not actually require any additional software
   to be installed, only minor reconfiguration of existing software:

  mgetty+sendfax

   mgetty+sendfax works with most Class 2 faxmodems. Courier does not use the
   spooling scripts found in the mgetty+sendfax package. Courier uses its own
   mail spool. A fax message is handled no differently than any other E-mail
   message. The only difference is that the E-mail message is addressed to
   <phonenumber@fax>.

   mgetty+sendfax should be configured with its default settings, EXCEPT as
   follows:

     * In /etc/mgetty+sendfax, the "max-tries-continue" setting must be set
       to "n".

  groff or troff, ghostscript, NetPBM

   Conversion of E-mail messages to faxes uses ghostscript, and groff. It
   should be possible to use the original UNIX troff instead of groff, but
   this has not been tested. Courier generates the fax cover page from the
   contents of the E-mail message's headers. The initial text portion of the
   E-mail message will appear as fax cover page comments. Note that the
   initial text portion of the E-mail message must be in plain text, not
   HTML. E-mail attachments will be converted and attached as additional fax
   pages. E-mail attachments may contain plain text, Postscript or PDF
   documents. Other attachments will result in the E-mail message being
   returned as undeliverable.

   Install the NetPBM library is installed, to add the ability to fax GIF,
   JPEG, and PNG images. Each image will be converted to a single fax page.
   Images in excess of 1500x1500 pixels (approximately) will be truncated,
   and color images will be dithered to black-and-white.

  Enabling faxing

   The configuration file /usr/lib/courier/etc/faxrc must be edited in order
   to enable faxing. This file sets up the dialing parameters, and the
   default file disables faxing by rejecting all phone numbers. The
   configuration file has extensive comments that explain how dialing
   parameters are set.

   Using webadmin to set up fax sending is highly recommended. A proper faxrc
   will automatically hide all the local daling conventions. Webadmin knows
   how to generate the dialing configuration for the North American dialing
   plan, with a configurable area code. Faxes should be addressed to a fixed
   ten digit area code+phone number address, <nnnxxxxxxx@fax>, which will be
   converted for dialing from the local area code appropriately. Webadmin can
   also optionally enable faxing to international 011 phone numbers. Webadmin
   can also fall back to a bare configuration where all phone numbers are
   dialed as-is, for locations outside of North America.

  Sending faxes

   E-mail messages may contain attachments. Courier combines all attachments
   in the message into a single fax transmission. Attachment types may be
   freely mixed. A single message may contain one plain text, and one PDF
   attachment, for example. It is possible to select certain options, as
   follows:

     * <phonenumber@fax-lowres>

       sends a low-resolution fax.

     * <phonenumber@fax-ignore>

       Ignore attachments that Courier doesn't know how to convert to a FAX
       image format. Normally, if an attachment cannot be converted the whole
       message is returned as undeliverable.

     * <phonenumber@fax-cover>

       sends only the cover page. This can be useful for .courier files. See
       the courierfax(8) manual page for an example.

   These options can be combined: <phonenumber>@fax-lowres-ignore>.

  Cover pages

   /usr/lib/courier/etc/faxcoverpage.tr is the troff source for the FAX cover
   page, which includes the first plain text section of the E-mail message.
   Do not attempt to play with faxcoverpage.tr without a clear understanding
   of troff. It is safe to make trivial changes (such as replacing the
   "FACSIMILE COVER PAGE" text).

  Dialing

   The /usr/lib/courier/etc/faxrc configuration file provides rudimentary
   phone number rewriting logic (stuff like dialing "9," to get outside line
   from a PBX). The default faxrc configuration file specifies a typical
   dialing configuration for the North American numbering plan, with seven
   digit local phone numbers, and 1+ten digit long distance phone numbers.
   The area code in the default faxrc configuration file is set to "999", you
   will need to change it to your area code (there are two places in faxrc
   where the area code needs to be set).

   In general, messages should be addressed to the full ten-digit phone
   numbers. The local area code will be stripped automatically, and "1" will
   be dialed before all other area codes. If this is done in practice, local
   area code changes will only require an update to faxrc, without any need
   to update the address book.

   Comments in the faxrc configuration file explain the format of the phone
   number rewriting rules, in the event that local phone system customization
   is required (for example, dialing 9 to get an outside line). Several
   places in North America now use ten digit local phone number overlays,
   with 1+ten digit long distance dialing. TODO: Use webadmin if you are not
   sure how to set this up.

  Security

   The default faxrc configuration file allows only locally-generated faxes.
   faxrc must be modified in order to accept faxes via ESMTP.

   Additionally, faxes are accepted via ESMTP only if the FAXRELAYCLIENT
   variable is set. See the makesmtpaccess(8) man page for additional
   information.

OPTIONAL: Configure inbound faxing

   mgetty has an option that runs a script called "new_fax" after it receives
   a fax. The default location for this script is either
   /usr/local/lib/etc/mgetty+sendfax/new_fax or /etc/mgetty+sendfax/new_fax.
   Consult your mgetty documentation to determine if the new_fax option is
   enabled, and the exact script location.

   Courier provides a script - /usr/lib/courier/share/faxmail/new_fax - that
   can be used as mgetty's new_fax script. This script converts incoming
   faxes to PNG images, and delivers it to a local mailbox. Simply copy this
   script to mgetty's etc directory (or install a soft link there), to
   automatically drop incoming faxes to a local mailboxes.

   The /usr/lib/courier/etc/faxnotifyrc configuration file specifies the
   mailbox that receives incoming faxes, and several other related options.

OPTIONAL: Install the Courier log analyzer

   The Courier log analyzer is a Perl script that generates log summaries for
   the Courier mail server. Courier-analog generates log summaries for
   incoming and outgoing SMTP connections, and IMAP and POP3 activity.
   courier-analog can generate output in text or HTML format.

   Courier-analog is not included in the main Courier tarball, it must be
   downloaded separately from http://www.courier-mta.org/download.php#analog.
   After downloading and installing this package, see the courier-analog
   manual page for more information.

Decommission your existing mail server

   This steps consists of flushing the mail queue of your existing mail
   server and removing it from the system.

   If you're using sendmail, edit your startup script, and start sendmail
   with the option '-q30m' only. Remove the -bd option. This causes sendmail
   to stop listening on port 25, and stay as a daemon process only for the
   purpose of running the queue every 30 minutes.

   If you're using Qmail, remove tcpserver from your system startup script.

   Wait for all existing mail to flush itself out, then permanently remove
   your existing server.

   Depending on your system, you may need to create a bunch of soft links,
   such as /usr/bin/sendmail, /usr/sbin/sendmail, /lib/sendmail, or
   /etc/sendmail that point to /usr/lib/courier/bin/sendmail. If you want to
   receive mail via UUCP you will also need to make sure that UUCP knows to
   find rmail in /usr/lib/courier/bin as well.

Sample init script

   You're now ready to configure your system to start Courier at system boot
   time (and shut it down at system shutdown). If your system uses system-V
   init scripts, here's a sample script that you can install in your
   /etc/rc?.ddirectories. This is a slightly modified version of the init
   script that's used in my RPM package (courier.sysvinit file in the source
   code tarball).

   NOTE: the following script may take a long time to finish, the very first
   time it runs. That's because the script automatically creates test SSL
   certificates the first time the script runs (provided that SSL support is
   available). This can take as much as 5-6 minutes on a slow machine.
   Subsequent starts should take only a few seconds.

 #! /bin/sh
 #
 # chkconfig: 2345 35 65
 # description: Courier - SMTP server
 #
 # NOTE: The 'restart' here does a "hard" stop, and a start.  Be gentle, use
 # "courierd restart" for a kindler, gentler, restart.
 #
 #

 prefix="/usr/lib/courier"
 exec_prefix="/usr/lib/courier"
 sysconfdir="/usr/lib/courier/etc"
 sbindir="${exec_prefix}/sbin"
 libexecdir="/usr/lib/courier/libexec"
 datadir="/usr/lib/courier/share"

 case "$1" in
 start)
         cd /
         # Start daemons.
         touch /var/lock/subsys/courier

         echo -n "Starting Courier mail server:"

         # First time after install create aliases.dat and makesmtpaccess.dat

         test -f ${sysconfdir}/aliases.dat || ${sbindir}/makealiases

         esmtpdcert=0

         . ${sysconfdir}/esmtpd
         case x$ESMTPDSTART in
         x[yY]*)
                 esmtpdcert=1
                 ;;
         esac

         test -f ${sysconfdir}/${ACCESSFILE}.dat || ${sbindir}/makesmtpaccess

         . ${sysconfdir}/esmtpd-msa
         case x$ESMTPDSTART in
         x[yY]*)
                 esmtpdcert=1
                 ;;
         esac

         test -f ${sysconfdir}/${ACCESSFILE}.dat || ${sbindir}/makesmtpaccess-msa

         ${sbindir}/courierfilter start
         echo -n " courierfilter"

         if test -x ${sbindir}/courierldapaliasd
         then
                 ${sbindir}/courierldapaliasd start
                 echo -n " courierldapaliasd"
         fi

         if test -f ${libexecdir}/courier/sqwebmaild
         then
                 ${sbindir}/webmaild start
                 echo -n " webmail"
         fi

         ${sbindir}/courier start
         echo -n " courierd"

         if test "$esmtpdcert" = 1
         then
 # If we do not have a certificate, make one up.

                 if test ! -f ${datadir}/esmtpd.pem
                 then
                         if test -x $COURIERTLS
                         then
                                 echo -n " generating-ESMTP-SSL-certificate..."
                                 ${sbindir}/mkesmtpdcert >/dev/null 2>&1
                         fi
                 fi
         fi

         . ${sysconfdir}/esmtpd
         case x$ESMTPDSTART in
         x[yY]*)

                 ${sbindir}/esmtpd start
                 echo -n " esmtpd"
                 ;;
         esac

         . ${sysconfdir}/esmtpd-msa
         case x$ESMTPDSTART in
         x[yY]*)

                 ${sbindir}/esmtpd-msa start
                 echo -n " esmtpd-msa"
                 ;;
         esac
        
         if test -x ${sbindir}/pop3d
         then
                 POP3DSTART=""
                 POP3DSSLSTART=""

                 if test -f ${sysconfdir}/pop3d
                 then
                         . ${sysconfdir}/pop3d
                 fi
                 case x$POP3DSTART in
                 x[yY]*)
                         ${sbindir}/pop3d start
                         echo -n " pop3d"
                         ;;
                 esac
                 if test -f ${sysconfdir}/pop3d-ssl
                 then
                         . ${sysconfdir}/pop3d-ssl
                 fi
                 case x$POP3DSSLSTART in
                 x[yY]*)
                         if test -x $COURIERTLS
                         then
 # If we do not have a certificate, make one up.

                                 if test ! -f ${datadir}/pop3d.pem
                                 then
                                         echo -n " generating-POP3-SSL-certificate..."

                                         ${sbindir}/mkpop3dcert >/dev/null 2>&1
                                 fi

                                 ${sbindir}/pop3d-ssl start && \
                                         echo -n " pop3d-ssl"
                         fi
                         ;;
                 esac
         fi

         if test -x ${sbindir}/imapd
         then
                 . ${sysconfdir}/imapd
                 case x$IMAPDSTART in
                 x[yY]*)
                         ${sbindir}/imapd start
                         echo -n " imapd"
                         ;;
                 esac
                 . ${sysconfdir}/imapd-ssl
                 case x$IMAPDSSLSTART in
                 x[yY]*)
                         if test -x $COURIERTLS
                         then
 # If we do not have a certificate, make one up.

                                 if test ! -f ${datadir}/imapd.pem
                                 then
                                         echo -n " generating-IMAP-SSL-certificate..."

                                         ${sbindir}/mkimapdcert >/dev/null 2>&1
                                 fi

                                 ${sbindir}/imapd-ssl start && \
                                         echo -n " imapd-ssl"
                         fi
                         ;;
                 esac
         fi

         echo ""
         ;;
 stop)
         echo -n "Stopping Courier mail server:"

         if test -x ${sbindir}/imapd
         then
                 ${sbindir}/imapd stop
                 echo -n " imapd"
         fi

         if test -x ${sbindir}/imapd-ssl
         then
                 ${sbindir}/imapd-ssl stop
                 echo -n " imapd-ssl"
         fi

         ${sbindir}/esmtpd-msa stop
         echo -n " esmtpd-msa"

         ${sbindir}/esmtpd stop
         echo -n " esmtpd"

         if test -x ${sbindir}/pop3d
         then
                 ${sbindir}/pop3d stop
                 echo -n " pop3d"
         fi

         if test -x ${sbindir}/pop3d-ssl
         then
                 ${sbindir}/pop3d-ssl stop
                 echo -n " pop3d-ssl"
         fi

         ${sbindir}/courier stop
         echo -n " courierd"

         if test -f ${libexecdir}/courier/sqwebmaild
         then
                 ${sbindir}/webmaild stop
                 echo -n " webmail"
         fi

         if test -x ${sbindir}/courierldapaliasd
         then
                 ${sbindir}/courierldapaliasd stop
                 echo -n " courierldapaliasd"
         fi

         ${sbindir}/courierfilter stop
         echo " courierfilter"
         ;;
 restart)
         $0 stop
         $0 start
         ;;
 esac
 exit 0

   The reason I test for the existence of the POP3 and IMAP server binaries
   is because I build the POP3 and IMAP servers as separate sub-packages,
   that do not have to be installed. These tests avoid the need for each
   sub-package to install its own startup script.
