[Dovecot] invoking LDA in .forward

[Jeremie Bouttier]

   Hi,

We're running a Debian server with system users where the mail is by 
default delivered by postfix and procmail, before being served by 
Dovecot (mail_location = mbox:~/Mail:INBOX=/var/mail/%u) or read by 
local MUAs, depending on users' preferences.

For people using mostly remote MUAs, it might be interesting to use 
Dovecot's LDA. I read on http://wiki.dovecot.org/LDA that this is 
possible using .forward files, however this fails on our system with :
file_lock_dotlock() failed with mbox file /var/mail/user: Permission denied
(/var/mail is 2775 for root:mail as recently discussed).

Is there a possible fix ? I also read that deliver is not designed to be 
run setuid root, I guess this also applies to being run setgid mail...

Regards,

   Jeremie