we are installing a ums server, and this server needs to get ums mails (mails with voice, fax, sms attached) forwarded from the zimbra mail server.

The ums mails have a sender like user1@fax.example.com, user1@sms.example.com and user1@voice.example.com. Mails for these domains should be routed to the ums server.

AFAIK I need to configure a transport map to do this. According to http://www.zimbra.com/forums/showthread.php?t=3928, I should be able to add one.

Since I am rather new to Postfix and Zimbra configuration, and I don't want to break my current configuration:

How can I add the transport map and what files do I need to change so Zimbra won't overwrite the changes at the next boot / update (examples would be great)?

Any help would be appreciated!