Before I get started, I love Zimbra, I'm administering several implementations... and this question has nothing to do with my personal views. I never thought I would have to migrate the other direction , but I have been assigned to a client who is moving from Zimbra to Exchange. Is there an easy tool for exporting Zimbra to Exchange?

They've been using several clients to connect to Zimbra (Evolution, Thunderbird, and Outlook), as well as using the web interface. I'm going to have a heavy load with the Thunderbird folks, who were popping it and not leaving it on the server.. but was hoping that a tool exists for the other 60% of the users so I can automate as much as possible.