[Dovecot] Shared Folder usage alpha3

[Ralf Zerres]

Dear List,

this is my first mail to this list.
I'v tried to carefully review all given information towards the Shared
Folder subject I could find in the archive / mailing list / wiki. And so
far I'm also aware that Timo hasn't put it on the active tasklist for
the 1.0 release.

Citing the track
	http://dovecot.org/pipermail/dovecot/2003-October/002493.html
I was wandering, wether any further attempt has been made, to use the
given functionality for real work. To be more precise, wether anybody
has done

        - delivery of mailboxes to a shared maildir 
        - offering these maildirs through a given namespace

Before bothering here without any local experience, I'v set up a
dov-server (1.0alpha3) on a debian sid. As an MTA postfix is doing the
job. Within postfix I did set up a virtual domain and the needed maps
(mailbox, alias). I'm able to deliver successful with the standard
postfix functionality to the given filesystem structure (fs=ext3).
If it is on any help, I can post the relevant config files.

As good practice, all mail is delivered to given mailbox-owner with 0600
permission for the new subdir. Hence, can't be seen by any
shared-maildir user (unless owner uid matches:)

>From here on I'v tried to switch from debians default postfix
delivery-strategy (mailbox_command = procmail -a "$EXTENSION") to given
dovcot deliver process (mailbox_command = /usr/lib/dovecot/deliver).
The primary aim is to define a strategy to deliver with 0660 rights
which will enable group read-write access to the given Mailstore.

I have adopted the dovecot.conf enableing a listening socket 

    ...

    default_mail_env = maildir:/home/%u/Maildir: \
        	           INDEX=/home/%u/MaildirIndex
        namespace private {
    	separator = /
    	prefix =
    	inbox = yes
    }
    namespace public {
	# the prefix needs to be postponed with the separator
   	prefix = Public/
   	# the location path given as [<mailbox-type>:]<path>/mailbox
   	location = maildir:/home/SharedMaildirs
   	separator = /
   	inbox = no
   	hidden = no
    }

        auth default {
        
          ...
        
          # using deliver through a socket
          socket listen {
            master {
              path = /var/run/dovecot/auth-master
              mode = 0666
            }
          }
    }
        
and configured the subsequent dovecot-deliver.conf

        ...
        
        auth_socket_path = /var/run/dovecot/auth-master
        mail = maildir:%h/Maildir/
        umask = 0007
        auth_verbose = yes
        use_syslog = yes
        
just to see, whether a manual call

    /usr/lib/dovecot/dovecot-deliver -d <user> <testmail

would do the trick. Well, I got the delivered mail, but files are
not installed with the etimated previledges.

Can someone can point me to the clou?

Greetings 
Ralf

PS: I also read about posix-acl's support. But my test's didn't allow
a successful read ....