[Dovecot] Shared Mailboxes, Per User SEEN flag and Mailing lists

[Reikan - Sidney Ferreira]

	Hi!
	Im making a small research about IMAP servers and it's features. As the 
subject suggests, I want make a shared mailbox, with per user \seen flag 
to work like a mailin-list works.
	The reason to use 1 shared folder is simple: Imagine 12k users sending 
1KB messages each week, it will be 12+ MB of useless information.
	Many people told me that IMAP could do this, but now seem that it is a 
little harder then what they made it look like.
	Finally, some EXIM users told me that Dovecot could handle it a little 
better than Courier, so, Im here to try to find more information about it.
	Follows the mail that I received from an EXIM user.

		Sidney

Bill Hacker wrote:
 > Reikan - Sidney Ferreira wrote:
 >
 >>     Does Exim works as IMAP?
 >>     Does it allow public folders?
 >>     The SEEN control is made by USER or MESSAGE?
 >>
 >>
 >
 > Exim is an MTA, not an IMAP (or POP) server.
 >
 > It works well with most, perhaps all, POP and IMAP servers.
 >
 > Two widely-used IMAP partners are courier-IMAP and Dovecot.
 > Both of these support POP as well as IMAP.
 > There are several others known to work.
 >
 > Folder sharing can be complex.  IMAP is more appropriate than POP, even
 > if other users are on POP.
 >
 > Exim can use Maildir MBox, and other storage types, can use several at
 > once, can select  the storage location, storage type, UID, GID, and
 > privilege mask from hard-coded, flat-file, db or RDBMS lookup, and can
 > create the storage if it does not already exist.
 >
 > All/any of the above can be done on a per-user, per-domain or per-sender
 > basis, and/or on combinations of the above.
 >
 > The rest is up to the IMAP and client configuration(s).
 >
 > Dovecot can handle Maildir, MBox and other.  Courier-IMAP is optimized
 > for Maildirs.
 >
 > Message state assignments are the responsibility of the retrieval agent
 > (IMAP/POP + MUA).
 > The MTA is not involved once the message has been delivered to storage
 > 9or distant server).
 >
 > As an MTA may process multiple valid messages per valid connection, not
 > all for the same valid user, or even same destination server, Exim does
 > routing and delivery in an area that is essentially per-user OR
 > per-destination sensitive, but always per-message relevant, i.e. -
 > normally handled one at a time at the 'decision making' points.
 >
 > HTH,
 >
 > Bill Hacker