[Dovecot] troubles with expire plugin

[Denis Fateyev]

Hello there,

Now I'm using `expire` plugin and getting troubles with cronjob (from
user `exim`):
/usr/sbin/dovecot --exec-mail ext /usr/libexec/dovecot/expire-tool.sh

Fatal: setgid(12(mail)) failed with euid=93(exim), gid=93(exim),
egid=93(exim): Operation not permitted (This binary should probably be
called with process group set to 12(mail) instead of 93(exim))

The same error occurs when I run this command from `exim` user with sudo.


My dovecot v1.2.11 configuration:

dovecot.conf
-----------------
...
    socket listen {
        master {
            path = /var/run/dovecot/auth-master
            mode = 0660
            user = exim
            group = mail
        }
        client {
            path = /var/spool/exim/private-auth
            mode = 0660
            user = exim
            group = mail
        }
    }
...

userdb-sql.conf
------------------------
# exim uid: 93, mail gid: 12
user_query = SELECT CONCAT('/var/mail/', maildir) AS home, \
    CONCAT('maildir:/var/mail/', maildir) AS mail, 93 AS uid, 12 AS gid, \
    CONCAT('*:storage=', quota, 'B') AS quota_rule, \
    'storage=90%% /usr/libexec/dovecot/quota_warning.sh 90' AS quota_warning \
    FROM mailbox WHERE username = '%u' AND active = '1'

password_query = SELECT username AS user, password, \
    CONCAT('/var/mail/', maildir) AS userdb_home, \
    CONCAT('maildir:/var/mail/', maildir) AS userdb_mail, \
    93 AS userdb_uid, 12 AS userdb_gid, \
    CONCAT('*:storage=', quota, 'B') AS userdb_quota_rule, \
    'storage=90%% /usr/libexec/dovecot/quota_warning.sh 90' AS
userdb_quota_warning \
    FROM mailbox WHERE username = '%u' AND active = '1'

( maybe, is any additional information required? )

All working fine with dovecot except this issue with `expire` plugin.
How to avoid it?
As I see, it's working if I run this command from `root` instead of
`exim`, but I don't think it will be right to leave it in the root's
crontab.

Thanks,

---
wbr, Denis.