/var/mail permission change from squeeze to wheezy

[Juha Heinanen <jh@tutpro.com>]

i noticed that permissions of /var/mail dir have changed from squeeze to
wheezy.

in squeeze i have

 $ ls -lsa
total 60
 4 drwxrwsrwt  2 root mail  4096 Mar 21 09:00 .

and in wheezy

 $ ls -lsa
total 60
 4 drwxrwsr-x  2 root mail  4096 Mar 21 09:00 .

the changes causes my emacs vm not being able to remove my emails from
/var/mail when it has copied them to my local folder.

i don't know if this is a bug or feature and if bug, which package i
should file a bug report against.

-- juha