distributionlists are not working

[Stefan]

Hello List,

I'm using kolab2 snapshot from 2004-10-16. Mails sent to the distributionlists 
are bounced. From postfix.log:

lmtp[27144]: D0C0040800D: to=<XXXXXXX_at_organet.com>, 
relay=/kolab/var/kolab/lmtp[/kolab/var/kolab/lmtp], delay=11, status=bounced 
(host /kolab/var/kolab/lmtp[/kolab/var/kolab/lmtp] said: 550-Mailbox unknown
.  Either there is no mailbox associated with this 550-name or you do not have 
authorization to see it. 550 5.1.1 User unknown (in reply to RCPT TO 
command))

May someone help me??

TIA
Stefan