Apr 10 11:48:28 mail deliver(user@domain.com): setgid(999) failed: Operation not permitted .. 999 is the gid of my vmail user. .. dovecot unix - n n - - pipe flags=DRhu user=vmail:mail argv=/usr/libexec/dovecot/deliver -d
So then you should use vmail:vmail here.
That did it. Thank you so much for your help.
I couldn't find a core dump file in the base_dir (/var/run/ dovecot). Is there a way to force a core dump?
ulimit -c unlimited
in the same shell before running dovecot should do it.
I still didn't get a core dump in /var/run/dovecot. Should I be looking somewhere else? That is the directory that the base_dir variable is set to in my dovecot.conf file.
I tried this with both the allow_all_users set and without it set. That was the fix though. By adding allow_all_users to my userdb static args, everything is running just fine.