Want to test on a spare server, how to config for talking to a remote server?

[gribbler]

I want to install as a test on another server than our mail server, I'd like zimbra to be able to check mail off our imap or pop on our main server, as well as be able to send out with the correct domain etc.
Is this doable? I think I did this a few years ago, and want to try it again

[phoenix]

You need to look at Split Domain in the wiki.