This documentation is for Dovecot v2.x, see wiki1 for v1.x documentation.

Shared Mailboxes in Dovecot Cluster

As mentioned in Director, you can't have multiple servers accessing the same user at the same time or it will lead into trouble. This becomes problematic with shared mailboxes, because two users who are sharing a folder may run in different servers. The solution here is to access the shared folders via IMAP protocol, which passes through the Dovecot proxies/directors so the actual filesystem access is done only by one server.

There are a couple of things still missing for this kind of use case:

Setting up user-shared folders

You'll need to setup master user logins to work for all the users. The logged in user becomes the master user. This way the ACLs are applied correctly.

namespace {
 type = shared
 prefix = shared/%%u/
 location = imapc:~/shared/%%u/ # cache for shared indexes
}
imapc_host = director-ip
imapc_master_user = %u
#imapc_user = # leave this empty. It'll be automatically filled with the destination username.
imapc_password = master-secret

plugin {
  acl_shared_dict = fs:posix:prefix=/nfs/shared-acls/
}

The shared dictionary needs to be accessible from all the backends. The possibilities for it are:

None: SharedMailboxes/ClusterSetup (last edited 2014-10-03 14:01:36 by TimoSirainen)