[Dovecot] Permissions for mail_temp_dir directory

[Timo Sirainen]

On Thu, 2013-06-06 at 08:06 +0200, Henrik Larsson wrote:
> I recently upgraded from 2.1.16 to 2.2.2 and started to receive the 
> following errors:
> imap(henrik at example.com): Error: 
> stat(/var/db/dovecot/dovecot.imap.mail.example.com.16128.3209d13f842955c2) 
> failed: Permission denied
> imap(henrik at example.com): Error: Temp file creation to 
> /var/db/dovecot/dovecot.imap.mail.example.com.16128. failed: Permission 
> denied
> imap(henrik at example.com): Error: 
> stat(/var/db/dovecot/dovecot.imap.mail.example.com.16501.0ddff1dc93cdbe6a) 
> failed: Permission denied
> imap(henrik at example.com): Error: Temp file creation to 
> /var/db/dovecot/dovecot.imap.mail.example.com.16501. failed: Permission 
> denied
> 
> I didn't have these before the upgrade. The current permissions for the 
> /var/db/dovecot directory is root:wheel 755.
> 
> What would be the correct permissions for the mail_temp_dir directory?

Mail processes (imap, pop3, lda, etc.) need to be able to write to
mail_temp_dir.

> first_valid_uid = 125
..
> userdb {
>    args = /usr/local/etc/dovecot/dovecot-sql.conf.ext
>    driver = sql
> }

If all of your mail users use UID 125, then 125 can own the directory.
If you use multiple UIDs, it needs to have the same permissions are
your /tmp.