First of all I'm very pleased about the zimbra mail server!!.
As a IT engineer i advise customers/install many networks, mostly microsoft exchange servers, but my hobby is with linux.
I just installed the open source version on my vmware workstation and it's working perfectly!.
In the near future i want to use my mobile phone to sync with zimbra, unfortunatly this is not possible with this free version.
Looking at the competition like "zarafa" they offer the mobile sync in the free version as well, which is a very interesting choice!
I would like to stay at Zimbra because i really like it, but paying so much money for a single user is not a option for me.
Please reconsider to make a free/cheap version of the mobile sync option so that many open source/single users can stay at Zimbra.
Keep up the good work!!