[Dovecot] Mailbox directory permissions (LDA, 0600 -> 0660, virtual users)

[Marcin Hłybin]

Hello,

I have a quite common dovecot configuration with virtual users support:
1. User configuration is stored in MySQL database.
2. Mailboxes are owned by vmail:vmail with permission 0600 or 
drwx------.

Is it possible to change mailbox mode to 0660?

Dovecot version is 2.1.7
Part of SQL configuration:

user_query = \
        SELECT \
                CONCAT_WS('/', home, u.uid, d.domain_name, u.user_name) AS 
home, \
                500 AS uid, \
                500 AS gid \
        FROM users u \
                LEFT JOIN domains d ON u.domain_id = d.id \
        WHERE \
                u.user_name = '%n' AND \
                d.domain_name = '%d' AND \
                u.active = 1

Regards.

--
M.