We are running Zimbra and I recently installed Entourage on my Macbook. I know there are a number of issues and for now I am just using Zimbra calendar in a seperate firefox window.
My current issues is that I am trying to get my personal folders to download and populate in the Entourage folder list complete with all the emails in them. The only way I have been able to accomplish this is I go to the highest level and view all of the folders and then I select the grayed out personal folder I want and select open. Then it downloads and is available in my folder list.
This is painfully slow as I have a large number of folders (over 400) and not to mention we have several Mac users in our company that want to switch to Entourage.
In case it matters I connect to our Zimbra server via IMAP.