On 12/23/2014 10:11 PM, Murray S. Kucherawy wrote: > -08 text says: > > "If the RFC5322.From domain does not exist in the DNS, Mail > Receivers > SHOULD direct the receiving SMTP server to reject the message. The > choice of mechanism for such rejection and the implications of those > choices are discussed in Section 9.3." > > I suggest removing it. Although a common anti-abuse mechanism, it's out > of scope for DMARC. > > > I disagree. DMARC operators all seem to apply this practice, so it's > correct to say that if you play this game, you reject mail from > non-existent domains. Essentially in this way DMARC is a profile of > RFC5321/RFC5322, which is perfectly acceptable. We are not updating > those standards here, merely profiling them.
The fact that its use happens to correlate with DMARC use is a distraction. For example, there are plenty of operators who use apply this check but do not use DMARC. If the test is documented in a specification, it should be in /one/ specification. Putting it into the DMARC spec means it has to be documented somewhere else, for the folk who don't use DMARC. Broadly, there are all sorts of things that DMARC operators commonly do, but that are not appropriate to document in the DMARC specification. DMARC concerns the domain name in the From: field and finding that it has a DMARC record associated with it. If there is no record associated with the domain name, then it is not participating in DMARC. There are other places to document other, common anti-abuse practices. The check for an MX is completely out of scope for the DMARC spec. d/ -- Dave Crocker Brandenburg InternetWorking bbiw.net _______________________________________________ dmarc mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmarc
