On 10.1.2012, at 11.34, l.chelchowski wrote:
Jan 10 10:15:06 lda: Debug: auth input: tester@domain.eu home=/home/vmail/domain.eu/tester/ mail=maildir:/home/vmail/domain.eu/tester/:INDEX=/var/mail/vmail/domain.eu/tester@domain.eu/index/public uid=101 gid=12 quota_rule=*:storage=2097 acl_groups=
Note that userdb lookup returns gid=12(mail)
Jan 10 10:15:06 lda(tester@domain.eu): Fatal: setresgid(12(mail),12(mail),101(vmail)) failed with euid=101(vmail): Operation not permitted
But you're running it with gid=101(vmail).
mail_gid = vmail mail_privileged_group = vmail mail_uid = vmail
Here you're also using gid=101(vmail). (The mail_privileged_group=vmail is a useless setting BTW)
userdb { args = /usr/local/etc/dovecot/dovecot-sql.conf driver = sql }
My guess for the best fix: Change the user_query not to return uid or gid fields at all.