See also:
http://www.zimbra.com/forums/adminis...end-users.html
-Haven't heard from those 2 in a while, tried to get in touch a bit ago ago as well, but they are a provider and can get busy. If I don't hear anything in PM/IM/Email this week I'll attach the old fbackup zimlet. I would really prefer that the original authors post it, but in the interest of an open source community I might just have to help it along.
-However, you can still make use of the REST methods listed in that thread to manually download .eml messages.