[Mailman-Users] Mailman reusing message-id, leads to duplicate message suppression

Richard Damon Richard at Damon-Family.org
Wed Nov 6 03:22:59 CET 2013

On 11/5/13, 6:59 PM, Stephen J. Turnbull wrote:
> Note that the subject is incorrect.  Mailman is not reusing the
> Message-ID, it is refusing to alter it which is correct behavior
> according to RFC 5322 (Message-ID is an originator field).
> I believe that according to RFC 5322 (and predecessors) Mailman SHOULD
> add a Resent-Message-ID to indicate that it handled the message, but I
> doubt this would change the duplicate-suppression behavior of Gmail
> and MS Exchange.
It is not clear to me that mailman should add the Resent-* headers. The
RFC states:

"Resent fields SHOULD be added to any message that is reintroduced by a
user into the transport system."

and later

"They MUST NOT be used in the normal processing of replies or other such
automatic actions on messages."

Mailman isn't really a "user", and is "automatic" so I think the second
clause is more applicable.

Richard Damon

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