to...@tuxteam.de writes:
> On Wed, Apr 12, 2023 at 12:38:37PM -0400, Jeffrey Walton wrote:
> > On Tue, Apr 11, 2023 at 10:12â¯PM The Wanderer <wande...@fastmail.fm>
> > wrote:
> > >
> > > ...
> > > Some mail services apparently treat this "discard incoming messages that
> > > look like duplicates of ones you already have a copy of" behavior as a
> > > feature; Gmail is the best-known example. That has problems when (as
> > > with this mailing list) the incoming copy is not identical to the one
> > > that was sent, even though it has the same Message-ID, but AFAIK they
> > > don't seem to care.
> >
> > I believe Message-Id's are supposed to be unique across space and
> > time. It sounds like discarding the duplicate is expected behavior (to
> > me).
>
FWIW, DKIM is not mailing list friendly. The DKIM signatures are from
the list, and does not match the sender domain name, preventing DKIM
authentication, even though the Message-ID:, References:, In-Reply-To:
SMTP header records are correct.
Exactly how the MTA handles this situation is kind of undocumented, and
left up to the MTA's configuration, which varies from one philosophy
to the next.
John
--
John Conover, cono...@panix.com, http://www.johncon.com/
