Virtual mailboxes
=================

(This plugin is available with dovecot version 1.2.x only)

Namespace configuration
-----------------------

First you'll have to create a <namespace> [Namespaces.txt] for the virtual
mailboxes, for example:

---%<-------------------------------------------------------------------------
﻿namespace private {
  prefix = virtual/
  separator = /
  location = virtual:~/Maildir/virtual
}
---%<-------------------------------------------------------------------------

After this you can create virtual mailboxes under '~/Maildir/virtual'. By
default it uses the "fs" layout, so you can create directories such as:

 * INBOX: '~/Maildir/virtual/INBOX/'
 * Sub/mailbox: '~/Maildir/virtual/Sub/mailbox/'

If you prefer to use Maildir++ layout instead, you can simply append
':LAYOUT=maildir++' to the location.

Virtual mailbox configuration
-----------------------------

For each virtual directory you need to create a 'dovecot-virtual' file. Its
syntax is like:

---%<-------------------------------------------------------------------------
<1+ mailbox patterns>
  <search program>
[<more mailbox patterns>
  <search program for these mailboxes>
[etc..]]
---%<-------------------------------------------------------------------------

Mailbox patterns can contain IMAP LIST-compatible "*" and "%" wildcards. They
are currently evaluated only when the virtual mailbox is being selected, so if
more mailboxes are created during that they aren't noticed.

"*" wildcard matches only one namespace at a time based on the namespace
prefix. For example if you have namespaces with an empty prefix and a prefix
"mail/":

 * '*' matches only mailboxes from the namespace with empty prefix
 * 'mail*' matches mailboxes beginning with name "mail" from the namespace with
   empty prefix
 * 'mail/*' matches only mailboxes from the mail/ namespace

It's possible to give negative matches for mailbox names by prefixing the
mailbox name with '-' character.

Search program is compatible with IMAP SEARCH command. Besides the standard
SEARCH key you may want to use X-MAILBOX key which matches the message's
original mailbox.

Examples
--------

List all messages with \Deleted flag in all mailboxes:

---%<-------------------------------------------------------------------------
# ~/Maildir/virtual/Trash/dovecot-virtual
*
  deleted
---%<-------------------------------------------------------------------------

List all unseen INBOX and work/* messages:

---%<-------------------------------------------------------------------------
# ~/Maildir/virtual/unseen/dovecot-virtual
INBOX
work/*
  unseen
---%<-------------------------------------------------------------------------

Create a GMail-style "conversation view" for INBOX which shows all threads that
have messages in INBOX, but shows all messages in the thread regardless of in
what mailbox they physically exist in:

---%<-------------------------------------------------------------------------
﻿# ~/Maildir/virtual/all/dovecot-virtual
﻿*
  all
---%<-------------------------------------------------------------------------

---%<-------------------------------------------------------------------------
# ~/Maildir/virtual/INBOX/dovecot-virtual
﻿virtual/all
﻿ inthread x-references2 x-mailbox INBOX
---%<-------------------------------------------------------------------------

Create a mailbox containing messages from all mailboxes except Trash and its
children:

---%<-------------------------------------------------------------------------
# ~/Maildir/virtual/all/dovecot-virtual
﻿*
-Trash
-Trash/*
  all
---%<-------------------------------------------------------------------------

Virtual POP3 INBOX
------------------

If you want POP3 INBOX to contain some or all mailboxes, you can do this in the
following way:

Namespace configuration:

---%<-------------------------------------------------------------------------
# The default namespace that is visible to IMAP clients
namespace private {
  prefix =
  separator = /
  list = yes
  hidden = yes
}

# Virtual namespace for the virtual INBOX.
namespace private {
  prefix = virtual/
  separator = /
  location = virtual:~/Maildir/virtual
  list = no
  hidden = yes
}

# Copy of the default namespace. We'll use this in dovecot-virtual file.
namespace private {
  prefix = RealMails/
  separator = /
  list = no
  hidden = yes
}
---%<-------------------------------------------------------------------------

Note that none of the namespaces have inbox=yes. This is because for IMAP users
you want the first namespace to have inbox=yes, but for POP3 users you want the
virtual namespace to have inbox=yes. This requires setting the inbox=yes
in<userdb extra fields> [UserDatabase.ExtraFields.txt]. For example with MySQL
you can can do this like:

---%<-------------------------------------------------------------------------
user_query = SELECT ..., \
  CASE '%s' WHEN 'pop3' THEN NULL ELSE 'yes' END AS namespace_1_inbox, \
  CASE '%s' WHEN 'pop3' THEN 'yes' ELSE NULL END AS namespace_2_inbox \
  WHERE ...
---%<-------------------------------------------------------------------------

Note the 1 and 2 in the middle of namespace_n_inbox. Those specify the
namespace's position, so 1 is the empty prefix namespace and 2 is the virtual
namespace.

Finally specify what the virtual INBOX looks like for POP3 users:

'~/Maildir/virtual/INBOX/dovecot-virtual' :

---%<-------------------------------------------------------------------------
RealMails/*
-RealMails/Trash
-RealMails/Trash/*
-RealMails/Spam
 all
---%<-------------------------------------------------------------------------

You'll have to use the <RealMails.txt>/ prefix if you want to use "*" wildcard,
otherwise it would match INBOX, which in turn would again lead to the virtual
INBOX and that would create a loop.

(This file was created from the wiki on 2009-03-02 04:42)
