[Dovecot] mail_privileged_group not working for dotlock files (1.1.6)

[Rob Mangiafico]

> Running dovecot 1.1.6 on centOS 5 and RHEL 5.
>
> With the settings:
> pop3_lock_session = yes
> mail_privileged_group = mail
> mail_location = mbox:~/:INBOX=/var/spool/mail/%u
> mbox_read_locks = fcntl
> mbox_write_locks = dotlock fcntl
>
> and /var/spool/mail permissions:
> drwxrwx--x   2 root   mail    4096 Nov 19 10:16 mail/
>
> Trying to connect via POP3 results in this error:
> ---
> Nov 19 09:31:01 lexiconn2 dovecot: child 32127 (pop3) killed with signal 11
>
> Nov 19 09:31:01 lexiconn2 dovecot: POP3(cerberus): file_lock_dotlock() failed 
> with mbox file /var/spool/mail/xxx: Permission denied
>
> Nov 19 09:31:01 lexiconn2 dovecot: pop3-login: Login: user=<xxx>, 
> method=PLAIN, rip=1.2.3.4, lip=5.6.7.8, secured
> ---
>
> The docs seem to indicate the above config / settings should work. Is this a 
> bug?
>
> The reason we have dotlock as the primary format is due to procmail LDA from 
> sendmail:
> ---
> procmail -v 2>&1|grep Locking
> Locking strategies:     dotlocking, fcntl()
> ---
>
> I assume we have to make the "mbox_write_locks" match the procmail locking...

We can use the workaround:
mail_access_groups = mail

But we'd prefer to use the safer method of "mail_privileged_group" to get 
dotlocking and POP3 mbox working with our current permissions. Just want 
to make sure we have things setup correctly. Thanks.

Rob