Dovecot log i mail queue problemi

Ako u /var/log/dovecot-lda.log imate ovakav upis :
Nov 28 08:00:44 lda: Debug: auth input: root system_groups_user=root uid=0 gid=0 home=/root
Nov 28 08:00:44 lda: Error: user root: Invalid settings in userdb: userdb returned 0 as uid
Nov 28 08:00:44 lda: Fatal: Invalid user settings. Refer to server log for more information.

A mail queue ima ovakve (naizgled neobjašnjive) neposlane mail poruke, koje bi DEFINITIVNO trebale da prođu :
# mailq
/var/spool/mqueue (6 requests)
—–Q-ID—– –Size– —–Q-Time—– ————Sender/Recipient———–
qAS6jiuo030459 2493 Wed Nov 28 07:45 MAILER-DAEMON
(Deferred: local mailer (/usr/libexec/dovecot/deliver) exited)

qAS2iVbS022888 312 Wed Nov 28 03:44
(Deferred: local mailer (/usr/libexec/dovecot/deliver) exited)

…

To znači da Dovecot ima problem sa time što mora da isporučuje poštu direktno korisniku root.
Zato u /etc/aliases treba preusmeriti mail koji ide na root korisnika, da ide na nekog drugog (kod mene na admin-postmaster korisnika). Paziti da ovo preusmeravanje ide tek POSLE svih procesa koji svoj mail usmeravaju na root!
# Person who should get root’s mail
admin-postmaster root

Naravno posle napraviti novu alias bazu, restartovati MTA, i pratiti logove.
# newaliases
# service MailScanner restart