A dozen users on our Eastern mail servers are being migrated to Lotus Domino so that they can be integrated into the BlackBerry Enterprise Server infrastructure. Domino will -- for these users -- be used as an IMAP store, so that the front-end infrastructure can remain the same. In order to do this, I have two changes to implement:
- Re-route e-mail.
- Re-route IMAP connections.
The first bit is easy, and I've described it before. I've created a
special Exim router that catches specific local parts (i.e. the bits
@example.com) and routes the e-mail to an available Domino
domino_route: driver = manualroute domains = example.com local_parts = lsearch;/etc/domino-users transport = remote_smtp route_list = * "domino.example.com : domiyes.example.com"
The second part is a bit more tricky, but in essence involves setting up an IMAP proxy that is able to distinguish who the calling user is. I'm using the excellent Perdition, a mail retrieval proxy, configuring it to route incoming IMAP connections to a standard server. For the dozen users, a regular expression map in Perdition suffices. Unfortunately, Lotus Domino doesn't support the IMAP IDLE command so the IMAP experience will be a bit lacking compared to using Dovecot, but there is little I can do about that.