----- Original Message ----- > From: "Hector Santos" <[email protected]> > To: "José Ferreira" <[email protected]> > Cc: [email protected] > Sent: Sunday, November 30, 2014 3:42:13 PM > Subject: Re: [dmarc-ietf] DMARC and Bounces (was: Indirect Mail Flows) > > All I reading (and it seems to be subsiding) are ML folks trying to > advocate avoiding domains with strong, restrictive policies. Well, > can't have it both ways. Intentional ignorance and expectation that > things will continue to work and integrate well, is in my strong > technical software engineering opinion, unrealistic. > > All parts need to fit together and since its a multi-component > integration problem, there are only a few packages that can do that. > That is what makes this a long time difficult problem to solve. You > have systems people, operations, networks, mailing list people, etc > and most have different goals and agendas. >
Forget about ML. I'm not only talking about ML but for a specific situation. Let me detail the issue. Most large system have several layers of defense. The edge system , after all teh checks, accepts the mail. When trying to deliver to the message store, it bounces ( the common example is the mailbox full )!. So the edge system generates a bounce message (MDN). Knowing that RFC5321.MailFrom will "<>". To be DMARC compliant the RFC5321.HELO/.EHLO name must be align with the RFC5322.From of the MDN. Again, this may be rare but should be referenced mainly because it can be easily overlooked. I guess I'm support Franck Martin when he wrote. "I guess these two (sendmail and postfix) are the backbone of many appliances... Therefore it is important to read http://trac.tools.ietf.org/html/rfc7208#section-10.1.3 on how to setup SPF to work with bounces." and adding that the RFC5321.MailFrom must be aligned. For Postfix, changing the From in MDNs is not trivial but also not that complicated. José Borges Ferreira. _______________________________________________ dmarc mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmarc
