Sooo!! The beta of Zimbra 6.08 is running fine on my Ubuntu 10.04 LTS 64bit on vSphere4.1 .
The only problem I realized is with statistics. Somehow the stats seems not to work until a few days.
When I restart the services (zmcontrol) everythings fine until a few days and the finally the daily report send's informations without one single mail delivery.
But mail transfer works without any problems.
Really strange. There is also no event in the logs.
But the rest - great!