It appears that Scott Kitterman <[email protected]> said: >> How about if it has a null MX and a DMARC record or DKIM keys? Remember >> that those records are at different names than the MX. ... >There's two ways we could go at this question: > >1. A domain that, except for the null mx, would fit the criteria for non- >existent. This would be kind of weird, since mull mx only makes sense if you >have an A/AAAA, but I wouldn't think existence of a null mx alone would be >enough to make the domain 'exist'. > >2. A domain which has an A/AAAA and null mx. Since it claims to be a no mail >domain, we could treat it as not existing for DMARC purposes. Since RFC 7505 >specifies null mx is for domains that don't accept mail, but is silent on >sending mail, these should probably exist for DMARC purposes. > >I think that your point is about #2 and I agree. #1 is definitely a corner >case, but if the only thing there is a null mx, I'd be quite comfortable >saying it doesn't exist.
It's about both. What if a domain has a null MX and a DMARC record? Maybe it has an SPF record, too. For your #2 you seem to be saying that if I send no-reply transactional mail, my DNS would look like this: notifiy.bigcorp.com. IN MX 0 . /* we don't receive replies /* IN A 0.0.0.0 /* make the domain exist */ _dmarc.notify.bigcorp.com. IN TXT "v=DMARC1; p=reject; ..." /* it's all aligned */ s._domainkey.notify.bigcorp.com. IN TXT "v=DKIM1; h=sha256; p=MIIBIjANB..." /* it's signed */ R's, John _______________________________________________ dmarc mailing list [email protected] https://www.ietf.org/mailman/listinfo/dmarc
