BuzzSaw Code via Postfix-users: > I've read the Postfix documentation trying to understand what the logs > are telling me, but this may still be a dumb question, so apologies in > advance. > > Another mail server within our own organization sends periodic > messages to us, and in the logs for those emails I see this: > > 2025-05-30T12:52:11.432101+00:00 smtp1 postfix/cleanup[423978]: > 406876023D: message-id=<> > > Does that mean the other system is sending me an email that lacks a > Message-ID header ?
It means there was no message ID, or a malformed Message-ID header with the value <>. You could match the latter with header_checks. > If so, is that something I should tell their system administrator to > fix or is Message-ID optional ? According to RFC 5322, the Message-ID SHOULD be present. It does not say MUST. See https://datatracker.ietf.org/doc/html/rfc5322#section-3.6 Wietse _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
