Hope you don't mind this silly message, but I just finished setting up my OS edition Zimbra server. This is the first time I have set up Zimbra, and the wiki and forums have proven invaluable. My poor little computer is now hosting Zimbra, a separate apache+tomcat server, as well as several virtual hosts to help separate the webmail traffic, administrative traffic, and web traffic. (This is a personal server, so I don't have a ton of traffic ) I also had to use imapsync (which I have used in the past).
For all of those who are having trouble setting up a NAT-ed Zimbra server, setting up the split domain is tricky. I had never worked with Bind before, and the first time I set it up, I only set it up for mail.[domain.com]. It still didn't work. When I reset it up to control all of [domain.com], I finally got it working. It is a bit of trouble, since I'll have to keep both my internal DNS and my external DNS provider in-sync, but at least email is working. I also found that using Webmin was a far easier way to edit the bind files!
Anyway, I'm happy that I was able to get it working simply by digging through the wiki and forums. I am really enjoying working with Zimbra so far.
- Phil DeJarnett