I happily run Zimbra OpenSource Edition on a server in a remote data centre.
I have been running a backup email server at home where I sync all domains, accounts and emails.
As many others can relate I am sure, I frequently reinstall and mess about with different distros at home - on various machines.
Everytime I install a new linux distro I go through the procedure of downloading and installing the latest Zimbra version - then creating all the domains - then creating all the users - then installing imapsync - then syncing all users emails.
To save myself some time I wrote a script that will read in domains, user accounts and their passwords - and create the lot on-the-fly.
N.B. - you must have a working copy of zimbra and imapsync running and of course access to your remote source Zimbra server.
The files must stay in the same folder, but of course you are more than welcome to edit or do whatever you like with them.
Cheers and have fun