[Mailman-Users] duplicate messages

[Adam McGreggor]

On Tue, Jan 05, 2010 at 08:28:58AM -0800, Ryan Stasel wrote:
> On Jan 5, 2010, at 06:59 , Mark Sapiro wrote:
> > 2) something in the outgoing MTA to you path that used to deliver only
> > 1 of multiple messages with duplicate message-ids changed and is no
> > longer dropping dups.
> 
> This looks like the case. It looks like Dovecot doesn't have any
> kind of duplicate suppression (at least, not that I can find

Dovecot is *not* an MTA. 

q.v. <http://wiki.dovecot.org/MailServerOverview>:
    "As an IMAP and POP3 server, Dovecot provides a way for mail-user
    agents [MUA] to access their mail. As such, Dovecot is NOT
    responsible for receiving mail from other servers. Dovecot
    presents mail already stored on the system to MUA's."

or, indeed,
    <http://www.dovecot.org/list/dovecot/2009-November/044640.html>

(I thought the expression "Dovecot is not a[n] MTA" was *somewhere on
the dovecot wiki, I can't seem to find it.)

de-duplication should be handled by the MTA before passing it to an
IMAP/POP server

I'd go back to the MTA(s) (Exim, Postfix, Sendmail, &c) config, and see
what's going on there.

-- 
``The reasonable man adapts himself to the world: the unreasonable one
  persists in trying to adapt the world to himself. Therefore all progress
  depends on the unreasonable man.'' (George Bernard Shaw)