IMAPD.CONF(5)

NAME
imapd.conf - IMAP configuration file

DESCRIPTION
/etc/imapd.conf is the configuration file for the Cyrus IMAP server. It defines local parameters for IMAP.

Each line of the /etc/imapd.conf file has the form

    option: value

where option is the name of the configuration option being set and value is the value that the configuration option is being set to.

Blank lines and lines beginning with ``#'' are ignored.

For boolean options, the values ``yes'', ``on'', ``t'', and ``1'' turn the option on, the values ``no'', ``off'', ``f'', and ``0'' turn the option off.

FIELD DESCRIPTIONS

The sections below detail options that can be placed in the /etc/imapd.conf file, and show each option's default value. Some options have no default value, these are listed with ``<no default>''. Some options default to the empty string, these are listed with ``<none>''.

admins: <empty string>
    The list of userids with administrative rights. Separate each userid with a space. Sites using Kerberos authentication may use separate "admin" instances.

Note that accounts used by users should not be administrators. Administrative accounts should not receive mail. That is, if user "jbRo" is a user reading mail, he should not also be in the admins line. Some problems may occur otherwise, most notably the ability of administrators to create top-level mailboxes visible to users, but not writable by users.

allowallsubscribe: 0
    Allow subscription to nonexistent mailboxes. This option is typically used on backend servers in a Murder so that users can subscribe to mailboxes that don't reside on their "home" server. This option can also be used as a workaround for IMAP clients which don't play well with nonexistent or unselectable mailboxes (eg. Microsoft Outlook).

allowanonymouslogin: 0
    Permit logins by the user "anonymous" using any password. Also allows use of the SASL ANONYMOUS mechanism.

allowapop: 1
    Allow use of the POP3 APOP authentication command.

Note that this command requires that SASL is compiled with APOP support, that the plaintext passwords are available in a SASL auxprop backend (eg. sasldb), and that the system can provide enough entropy (eg. from /dev/urandom) to create a challenge in the banner.

allownewnews: 0
    Allow use of the NNTP NEWNEWS command.

Note that this is a very expensive command and should only be enabled when absolutely necessary.

allowplaintext: 1
    Allow the use of cleartext passwords on the wire.

allowusermoves: 0
    Allow moving user accounts (with associated meta-data) via RENAME or XFER.

Note that measures should be taken to make sure that the user being moved is not logged in, and can not login during the move. Failure to do so may result in the user's meta-data (seen state, subscriptions, etc) being corrupted or out of date.

altnamespace: 0
    Use the alternate IMAP namespace, where personal folders reside at the same level in the hierarchy as INBOX.

This option ONLY applies where interaction takes place with the client/user. Currently this is limited to the IMAP protocol (imapd) and Sieve scripts (lmtpd). This option does NOT apply to admin tools such as cyradm (admins ONLY), reconstruct, quota, etc., NOR does it affect LMTP delivery of messages directly to mailboxes via plus-addressing.

autocreatequota: 0
    If nonzero, normal users may create their own IMAP accounts by creating the mailbox INBOX. The user's quota is set to the value if it is positive, otherwise the user has unlimited quota.

configdirectory: <none>
    The pathname of the IMAP configuration directory. This field is required.

debug_command: <none>
    Debug command to be used by processes started with -D option. The string is a C format string that gets 3 options: the first is the name of the executable (without path). The second is the pid (integer) and the third is the service ID. Example: /usr/local/bin/gdb /usr/cyrus/bin/%s %d

defaultacl: anyone lrs
    The Access Control List (ACL) placed on a newly-created (non-user) mailbox that does not have a parent mailbox.

defaultdomain: <none>
    The default domain for virtual domain support

defaultpartition: default
    The partition name used by default for new mailboxes.

deleteright: c
    The right that a user needs to delete a mailbox.

duplicatesuppression: 1
    If enabled, lmtpd will suppress delivery of a message to a mailbox if a message with the same message-id (or resent-message-id) is recorded as having already been delivered to the mailbox. Records the mailbox and message-id/resent-message-id of all successful deliveries.

foolstupidclients: 0
    If enabled, only list the personal namespace when a LIST "*" is performed. (it changes the request to a LIST "INBOX*"

fulldirhash: 0
    If enabled, uses an improved directory hashing scheme which hashes the entire username instead of using just the first letter. This changes hash algorithm used for quota and user directories and if hashimapspoolR is enabled, the entire mail spool.

Note that this option can NOT be changed on a live system. The server must be quiesced and then the directories moved with the rehash utility.

hashimapspool: 0
    If enabled, the partitions will also be hashed, in addition to the hashing done on configuration directories. This is recommended if one partition has a very bushy mailbox tree.

hostname_mechs: <none>
    Force a particuar list of SASL mechanisms to be used when authenticating to the backend server hostname (where hostname is the short hostname of the server in question). If it is not specified it will query the server for available mechanisms and pick one to use. - Cyrus Murder

hostname_password: <none>
    The password to use for authentication to the backend server hostname (where hostname is the short hostname of the server) - Cyrus Murder

idlesocket: {configdirectory}/socket/idle
    Unix domain socket that idled listens on.

ignorereference: 0
    For backwards compatibility with Cyrus 1.5.10 and earlier -- ignore the reference argument in LIST or LSUB commands.

imapidlepoll: 60
    The interval (in seconds) for polling the mailbox for changes while running the IDLE command. This option is used when idled can not be contacted or when polling is used exclusively. The minimum value is 1. A value of 0 will disable polling (and disable IDLE if polling is the only method available).

imapidresponse: 1
    If enabled, the server responds to an ID command with a parameter list containing: version, vendor, support-url, os, os-version, command, arguments, environment. Otherwise the server returns NIL.

implicit_owner_rights: lca
    The implicit Access Control List (ACL) for the owner of a mailbox.

ldap_base: <none>
    Contains the LDAP base dn for the LDAP ptloader module

ldap_filter: <none>
    Contains the ldap filter to use when looking up the user id. The occurance of any %u in the string will be replaced with the canonicalized user id

ldap_servers: <none>
    Contains a list of the URLs of all the LDAP servers when using the LDAP PTS module.

ldap_sasl: 1
    Use SASL for LDAP binds in the LDAP PTS module.

ldap_sasl_authc: <none>
    Force the use of a particular SASL authentication ID for the LDAP server

ldap_sasl_authz: <none>
    Force the use of a particular SASL authorization ID for the LDAP server

ldap_sasl_mech: <none>
    Force the use of a particular SASL mechanism for LDAP authentication

ldap_sasl_password: <none>
    Password for the LDAP SASL mechanism (if needed)

ldap_sasl_realm: <none>
    Force the use of a particular SASL realm for LDAP authentication

ldap_member_attribute: memberOf
    The multi-valued attribute name for an entity that lists its groups.

lmtp_downcase_rcpt: 0
    If enabled, lmtpd will convert the recipient address to lowercase (up to a '+' character, if present).

lmtp_over_quota_perm_failure: 0
    If enabled, lmtpd returns a permanent failure code when a user's mailbox is over quota. By default, the failure is temporary, causing the MTA to queue the message and retry later.

lmtpsocket: {configdirectory}/socket/lmtp
    Unix domain socket that lmtpd listens on, used by deliver(8). This should match the path specified in cyrus.conf(5).

loginrealms: <empty string>
    The list of remote realms whose users may log in using cross-realm authentications. Seperate each realm name by a space. (A cross-realm identity is considered any identity returned by SASL with an "@" in it.)

loginuseacl: 0
    If enabled, any authentication identity which has a rights on a user's INBOX may log in as that user.

logtimestamps: 0
    Include notations in the protocol telemetry logs indicating the number of seconds since the last command or response.

mailnotifier: <none>
    Notifyd(8) method to use for "MAIL" notifications. If not set, "MAIL" notifications are disabled.

maxmessagesize: 0
    Maximum incoming LMTP message size. If non-zero, lmtpd will reject messages larger than maxmessagesize bytes. If set to 0, this will allow messages of any size (the default).

mupdate_connections_max: 128
    The max number of connections that a mupdate process will allow, this is related to the number of file descriptors in the mupdate process. Beyond this number connections will be immedately issued a BYE response.

mupdate_authname: <none>
    The SASL username (Authentication Name) to use when authenticating to the mupdate server (if needed).

mupdate_password: <none>
    The SASL password (if needed) to use when authenticating to the mupdate server.

mupdate_port: 2004
    The port of the mupdate server for the Cyrus Murder

mupdate_realm: <none>
    The SASL realm (if needed) to use when authenticating to the mupdate server.

mupdate_retry_delay: 20
    The base time to wait between connection retries to the mupdate server.

mupdate_server: <none>
    The mupdate server for the Cyrus Murder

mupdate_workers_start: 5
    The number of mupdate worker threads to start

mupdate_workers_minspare: 2
    The minimum number of idle mupdate worker threads

mupdate_workers_maxspare: 10
    The maximum number of idle mupdate worker threads

mupdate_workers_max: 50
    The maximum number of mupdate worker threads (overall)

mupdate_username: <empty string>
    The SASL username (Authorization Name) to use when authenticating to the mupdate server

netscapeurl: http://asg.web.cmu.edu/cyrus/imapd/netscape-admin.html
    If enabled at compile time, this specifies a URL to reply when Netscape asks the server where the mail administration HTTP server is. The default is a site at CMU with a hopefully informative message; administrators should set this to a local resource with some information of greater use.

newsmaster: news
    Userid that is used for checking access controls when executing Usenet control messages. For instance, to allow articles to be automatically deleted by cancel messages, give the "news" user the automatically created, deleted and renamed by the corresponding control messages, give the "news" user the 'c' right on the desired mailbox hierarchies.

newspeer: <none>
    A string of the form peer[:wildmat] where 'peer' is the fully qualified hostname of the upstream news server to which articles should be fed and 'wildmat' is an optional wildmat which specifies which groups should be fed. If no wildmat is specified, all groups are fed.

    A '@' may be used in place of '!' to prevent feeding articles cross-posted to the given group, otherwise cross-posted are fed if any part of the wildmat matches. For example, the string "peer.example.com:*,!control.*,@local.*" would feed all groups except control messages and local groups to peer.example.com. In the case of cross-posting to local groups, these articles would not be fed.

newspostuser: <none>
    Userid used to deliver usenet articles to newsgroup folders (usually via lmtp2nntp). For example, if set to "post", email sent to "post+comp.mail.imap" would be delivered to the "comp.mail.imap" folder.

    When set, the Cyrus NNTP server will add a To: header to each incoming usenet article. This To: header will contain email delivery addresses corresponding to each newsgroup in the Newsgroups: header. By default, a To: header is not added to usenet articles.

newsprefix: <none>
    Prefix to be prepended to newsgroup names to make the corresponding IMAP mailbox names.

notifysocket: {configdirectory}/socket/notify
    Unix domain socket that the new mail notification daemon listens on.

partition-name: <none>
    The pathname of the partition name. At least one field, for the partition named in the defaultpartition option, is required. For example, if the value of the defaultpartion option is default, then the partition-default field is required.

plaintextloginpause: 0
    Number of seconds to pause after a successful plaintext login. For systems that support strong authentication, this permits users to perceive a cost of using plaintext passwords. (This does not affect the use of PLAIN in SASL authentications.)

popexpiretime: -1
    The number of days advertised as being the minimum a message may be left on the POP server before it is deleted (via the CAPA command, defined in the POP3 Extension Mechanism, which some clients may support). "NEVER", the default, may be specified with a negative number. The Cyrus POP3 server never deletes mail, no matter what the value of this parameter is. However, if a site implements a less liberal policy, it needs to change this parameter accordingly.

popminpoll: 0
    Set the minimum amount of time the server forces users to wait between successive POP logins, in minutes. The default is 0.

poptimeout: 10
    Set the length of the POP server's inactivity autologout timer, in minutes. The minimum value is 10, the default.

postmaster: postmaster
    Username that is used as the 'From' address in rejection MDNs produced by sieve.

postuser: <empty string>
    Userid used to deliver messages to shared folders. For example, if set to "bb", email sent to "bb+shared.blah" would be delivered to the "shared.blah" folder. By default, an email address of "+shared.blah" would be used.

proxy_authname: proxy
    The authentication name to use when authenticating to a backend server in the Cyrus Murder.

proxy_password: <none>
    The default password to use when authenticating to a backend server in the Cyrus Murder. May be overridden on a host-specific basis using the hostname_password option.

proxy_realm: <none>
    The authentication realm to use when authenticating to a backend server in the Cyrus Murder

proxyd_allow_status_referral: 0
    Set to true to allow proxyd to issue referrals to clients that support it when answering the STATUS command. This is disabled by default since some clients issue many STATUS commands in a row, and do not cache the connections that these referrals would cause, thus resulting in a higher authentication load on the respective backend server.

proxyservers: <none>
    A list of users and groups that are allowed to proxy for other users, seperated by spaces. Any user listed in this will be allowed to login for any other user: use with caution.

ptscache_timeout: 10800
    The timeout (in seconds) for the PTS cache database when using the auth_krb_pts authorization method (default: 3 hours).

ptskrb5_slashtodot: 0
    When using the AFSKRB ptloader module with Kerberos 5 canonicalization, force the '/' in Kerberos 5 principals to be canonicalized to a '.' (to make PTS lookups easier)

quotawarn: 90
    The percent of quota utilization over which the server generates warnings.

quotawarnkb: 0
    The maximum amount of free space (in kB) in which to give a quota warning (if this value is 0, or if the quota is smaller than this amount, than warnings are always given).

reject8bit: 0
    If enabled, lmtpd rejects messages with 8-bit characters in the headers. Otherwise, 8-bit characters are changed to `X'. (A proper soultion to non-ASCII characters in headers is offered by RFC 2047 and its predecessors.)

rfc2046_strict: 0
    If enabled, imapd will be strict (per RFC 2046) when matching MIME boundary strings. This means that boundaries containing other boundaries as substrings will be treated as identical. Since enabling this option will break some messages created by Eudora 5.1 (and earlier), it is recommended that it be left disabled unless there is good reason to do otherwise.

sasl_auto_transition: 0
    If enabled, the SASL library will automatically create authentication secrets when given a plaintext password. See the SASL documentation.

sasl_maximum_layer: 256
    Maximum SSF (security strength factor) that the server will allow a client to negotiate.

sasl_minimum_layer: 0
    The minimum SSF that the server will allow a client to negotiate. A value of 1 requires integrity protection; any higher value requires some amount of encryption.

sasl_option: 0
    Any SASL option can be set by preceeding it with "sasl_". This file overrides the SASL configuration file.

sasl_pwcheck_method: <none>
    The mechanism used by the server to verify plaintext passwords. Possible values include "auxprop", "saslauthd", and "pwcheck".

sendmail: /usr/sbin/sendmail
    The pathname of the sendmail executable. Sieve invokes sendmail for sending rejections, redirects and vacation responses.

servername: <none>
    This is the hostname visible in the greeting messages of the POP, IMAP and LMTP daemons. If it is unset, then the result returned from gethostname(2) is used.

sharedprefix: Shared Folders
    If using the alternate IMAP namespace, the prefix for the shared namespace. The hierarchy delimiter will be automatically appended.

sieve_maxscriptsize: 32
    Maximum size (in kilobytes) any sieve script can be, enforced at submission by timsieved(8).

sieve_maxscripts: 5
    Maximum number of sieve scripts any user may have, enforced at submission by timsieved(8).

sievedir: /var/imap/sieve
    If sieveusehomedir is false, this directory is searched for Sieve scripts.

sievenotifier: <none>
    Notifyd(8) method to use for "SIEVE" notifications. If not set, "SIEVE" notifications are disabled.

This method is only used when no method is specified in the script.

sieveusehomedir: 0
    If enabled, lmtpd will look for Sieve scripts in user's home directories: ~user/.sieve.

singleinstancestore: 1
    If enabled, lmtpd and nntpd attempt to only write one copy of a message per partition and create hard links, resulting in a potentially large disk savings.

skiplist_unsafe: 0
    If enabled, this option forces the skiplist cyrusdb backend to not sync writes to the disk. Enabling this option is NOT RECOMMENDED.

soft_noauth: 1
    If enabled, lmtpd returns temporary failures if the client does not successfully authenticate. Otherwise lmtpd returns permanant failures (causing the mail to bounce immediately).

srvtab: <empty string>
    The pathname of srvtab file containing the server's private key. This option is passed to the SASL library and overrides its default setting.

syslog_prefix: <none>
    String to be appended to the process name in syslog entries.

temp_path: /tmp
    The pathname to store temporary files in

timeout: 30
    The length of the IMAP server's inactivity autologout timer, in minutes. The minimum value is 30, the default.

tls_ca_file: <none>
    File containing one or more Certificate Authority (CA) certificates.

tls_ca_path: <none>
    Path to directory with certificates of CAs. This directory must have filenames with the hashed value of the certificate (see openssl(XXX)).

tls_cert_file: <none>
    File containing the certificate presented for server authentication during STARTTLS. A value of "disabled" will disable SSL/TLS.

tls_cipher_list: DEFAULT
    The list of SSL/TLS ciphers to allow. The format of the string is described in ciphers(1).

tls_key_file: <none>
    File containing the private key belonging to the server certificate. A value of "disabled" will disable SSL/TLS.

tls_require_cert: 0
    Require a client certificate for ALL services (imap, pop3, lmtp, sieve).

tls_session_timeout: 1440
    The length of time (in minutes) that a TLS session will be cached for later reuse. The maximum value is 1440 (24 hours), the default. A value of 0 will disable session caching.

umask: 077
    The umask value used by various Cyrus IMAP programs.

username_tolower: 1
    Convert usernames to all lowercase before login/authenticate. This is useful with authentication backends which ignore case during username lookups (such as LDAP).

userprefix: Other Users
    If using the alternate IMAP namespace, the prefix for the other users namespace. The hierarchy delimiter will be automatically appended.

unix_group_enable: 1
    Should we look up groups when using auth_unix (disable this if you are not using groups in ACLs for your IMAP server, and you are using auth_unix with a backend (such as LDAP) that can make getgrent() calls very slow)

unixhierarchysep: 0
    Use the UNIX separator character '/' for delimiting levels of mailbox hierarchy. The default is to use the netnews separator character '.'.

virtdomains: 0
    Enable virtual domain support

SEE ALSO

imapd(8), pop3d(8), nntpd(8), lmtpd(8), timsieved(8), idled(8), notifyd(8), deliver(8), master(8), ciphers(1)