Strange got half my lists working again including the default mailman account and all pre 3.0.5 lists.
So newly created lists don't work (sending a mail to it) but you can add yourself to the list and then all verification mails work.
got still some errors in the log files:
table "mysql:/etc/postfix/mysql-virtual_client.cf": empty query string -- ignored
database /var/lib/mailman/data/virtual-mailman.db is older than source file /var/lib/mailman/data/virtual-mailman
imapd: Error reading ACLs for : Invalid argument
think they are all related to the problem
Hope you got some tips