ActiveSync on Android: Encrypted Mail

Hi,

When synchronizing Kolab 3 with Android all E-Mails are "encrypted" and 
can't be read. It downloads the mails, displays the subject and sender 
but the body is "encrypted" and offers me to "decrypt" the E-Mail (what 
of course fails). I've also synchronized to my Nokia N9 which displays 
the E-Mails, so there seems to be something special with Android. Any 
hints on this?

Cheers,
Tobias