On Tue, 10 Oct 2023 10:14:10 -0700, Chris Cappuccio wrote: > The Message-ID should be added to any message that doesn't have one. > An existing Message-ID should not be removed or changed. > > The RFC says it "MAY be applied when necessary by an originating SMTP server" > so the port numbers aren't a terrible idea, but it leaves open plenty > of room to not add one if someone isn't following the 465/587 scheme.
But smtpd may not be the originating SMTP server. For "local" messages (that originated on the server) it knows to add the Message-ID if missing. I don't think it should be adding it to relayed messages. Messages received on the submission port are special, they need to be treated as local even though they originated elsewhere. - todd
