[Dovecot] Shared folders not woking for me

[Nagy László]

I also could create a shared folder. The problem was that I had to use 
'.Tasks' instead of 'Tasks'.
> Now I'm having permission problems, but will solve soon. :-)
I was wrong. :-) Short description follows.

I create a new group, and add two users to it:

pw groupadd das
pw usermod gandalf -g das
pw usermod tony -g das

Then I create a shared folder:

mkdir /var/mail/public
cd /var/mail/public
mkdir dovecot-shared
mkdir .Tasks
mkdir .Tasks.gandalf
mkdir .Tasks.tony
cp dovecot-shared .Tasks
cp dovecot-shared .Tasks.gandalf
cp dovecot-shared .Tasks.tony
cd /var/mail/public
chmod -R 770 public
chown -R davecot:das public

Then I create this namespace:

namespace public {
  separator = /
  prefix = Public/
  location = maildir:/var/mail/public
}

Then I start dovecot, and try to login with gandalf, and subscribe to 
'Public/Tasks', 'Public/Tasks/gandalf' and 'Public/Tasks/tony' folders. 
Fine.
The main point is to allow users in the 'das' group to read/write 
messages in the public folders above.

Now here are the problems:

   1. When I login and subscribe with user gandalf, dovecot creates the
      cur,new,tmp subfolders and dovecot.index,dovecot.index.cache and
      dovecot.index.log files. The files are okay - they are owned by
      gandalf:das, and their permission is 660. But the 'new' 'cur' and
      'tmp' folders are owned by dovecot:mail. Why?
   2. All right, I go to /var/mail/ again, and do "chown -R dovecot:das
      public ; chmod -R 770 dovecot:das public". This is still bad. I
      simply cannot subscribe to these folders. I think I know why. The
      server side process is running under 'gandalf:mail' or
      'tony:mail'. The dirs have permission 770, but owned by 'dovecot:das'.

How can I create a group of users which can use the same public folders? 
(Other users should not!)

Thanks,

   Laszlo