[Dovecot] imap auto create mailbox: we're not in group 8(mail)

[Joseph Tam]

Adrian Zaugg writes:

> How can I configure the auto create mailbox feature that it works and
> let run LMTP and IMAP process as user %u and group mail and let create
> the mailboxes in /var/mail as (example user tester) with the following
> permissions:
>
> /var/mail:
>
> drwxrwx--x  root     mail        3072 Dec 18 01:43 .
> drwx------  tester   tester      1024 Jan 09 12:53 tester

This is probably what you need:

 	# Group to enable temporarily for privileged operations. Currently this is
 	# used only with INBOX when either its initial creation or dotlocking fails.
 	# Typically this is set to "mail" to give access to /var/mail.
 	mail_privileged_group = mail

> ...or do I need a different approach?

You could also

 	chmod 1777 /var/mail

but this will allow arbitrary uses who have filesystem access to create
their own files here, and maybe DoS a new user from being created (or
maybe even anticipate a new mailbox, create one with mode 0777 and
wait to intercept mail?).

Joseph Tam <jtam.home at gmail.com>