I have, regrettably, given up on zarafa as production ready software hosted on SME. In all fairness, the warning is clear on the SME Zarafa Wiki. Very promising package but not ready for prime time.
I really liked Zarafa but have neither the time nor talent to bet the farm on it for work. I have moved the company's email system off SME to a commercially hosted solution. Version upgrade 6.30.6 killed it for me. SME remains our file and backup server of choice, just not for email.
Sorry to shang-hi your post.
MJ