Mailbox alias plugin
====================

Requires v2.1.10+ (and currently mailbox_list_index=no). This plugin can be
used to configure mailbox aliases, which on the filesystem level are symlinks
to other mailboxes. This doesn't magically solve the problem of showing clients
e.g. multiple Sent mailboxes, but it can be used to make sure that all of the
different variants will have the same mails in them. Unfortunately it also
means that some clients will download the same mails to local cache multiple
times.

The way it works is that:

 * The aliases won't be visible until the mailbox is CREATEd
 * When alias is CREATEd, a symlink is created to the original mailbox. If the
   original mailbox didn't exist yet, it's also created.
 * If a mailbox with the same name as alias was already created before this
   plugin was enabled, its behavior won't change unless it's deleted.
 * When alias is DELETEd, the symlink is removed without deleting any of the
   mails.
 * The original mailbox can't be DELETEd while it still has aliases.
 * Mailbox can't be RENAMEd if it's an alias or if it has aliases.

Example configuration where "Sent" is the real mailbox and it has aliases "Sent
Messages" and "Sent Items":

---%<-------------------------------------------------------------------------
mail_plugins = $mail_plugins mailbox_alias
plugin {
  mailbox_alias_old = Sent
  mailbox_alias_new = Sent Messages
  mailbox_alias_old2 = Sent
  mailbox_alias_new2 = Sent Items
}

# Usually you want the Sent mailbox to be autocreated and advertised as
SPECIAL-USE \Sent:
namespace inbox {
  mailbox Sent {
    auto = create # or subscribe
    special_use = \Sent
  }
}
---%<-------------------------------------------------------------------------

(This file was created from the wiki on 2019-06-19 12:42)
