From: "Jack Knowlton" on 2 Mar 2010 02:06
I have a Postfix virtual users setup based on mysql tables. Messages are
stored in Maildir format. Maildirs are owned by "vmail:vmail" .
I want another user to be able to read those Maildir files so I added him
to the "vmail" group.
Unfortunately Postfix seems to create the directory structure with
permissions 700 when I actually need 740 (group readable)
dsrv:~# ls -alh /var/mail/virtual/domain.com/
drwx--S--- 5 vmail vmail 120 2010-03-02 07:52 kvf2igxx