The open source Zarafa version 6.20 is still a beta version. The SME zarafa rpm is still only an alpha version. Fine for testing, but not a great idea for a production machine.
I have been running Zarafa on a test machine and am very impressed. I would like nothing better than to upgrade it to production status. Darrell has been doing a fine job of spearheading the SME portion of the project. I think some more patience is required..