I've managed to get Zimbra behaving pretty well with all desktop clients bar one - Novell/Ximian Evolution So far this is what I've found.

It looks like subfolder viewing is a bit intermittent and I get a strange un-named empty folder show up all the time:

When I connect to the server with Evolution the first thing I get is a SSL cert warning - not a big issue as it's self signed, but when I look at the warning it shows the CN as the server and OU, O etc as Zimbra in the US:

Could I change these details by using
zmcertinstall mailbox <cert.file>