Solved Issue with mail delivery / gid in /etc/virtual/domain/passwd

[sneer]

Hi All,

Today I've been notified about one mail delivered multiple times to at least one mailbox.
What I've found in mail.log:

lmtp: Fatal: master: service(lmtp): child 25964 returned error 89 (Fatal failure)

going on - dovecot-lmtp-errors.log

lmtp(user@domain)<16171><dd/CG2pX3mErPwAAqWA3Tw>: Fatal: setgid(8(mail) from userdb lookup) failed with euid=509(idmuser), gid=12(man), egid=12(man): Operation not permitted (This binary should probably be called with process group set to 8(mail) instead of 12(man))

/etc/virtual/DOMAIN/passwd

sianko:$1$HHaa$$:511:8::/home/LOGIN/imap/DOMAIN/USER:/bin/false:userdb_quota_rule=*:bytes=101M

It looks, that every email user modification i DA panel (this time I've changed quota only) GID i changing from 12 (man) (this is incorrect, but works now that way) to 8 (mail) (this is correct)

I'm running Debian 10, system was migrated from centos 6 few weeks ago, so I'm not sure if this is the reason.

Is is possible to change somewhere GID for this? How to deal with this issue?

 

[sneer]

I'll answer to myself.

It looks like error in conversion from Centos to Debian.
/etc/virtual was synchronized by rsync. GID of mail group on old system was different than on new one.
Now I've changed GID in all /etc/virtual/*/passwd files to correct one
Also fixed perms under /home/$USER/imap from :man to :mail

find /home -user man -exec chown :mail {} \;

Checking logs, everything looks fine so far.