It appears that Dan Mahoney via mailop <[email protected]> said: >All, > >A little background: > >In prior versions of DMARC, one was encouraged to use a "public suffix list" >to determine where the apex of an >organizational domain was (thus assuming that the highest a search could go >was at the public suffix). > >DMARCbis changed this, saying basically that you should traverse upward >through the DNS until you encounter a tag with >psd=n (indicating that you're an apex of an organization), or psd=y >(indicating that you're the "public suffix" (e.g. >.com, .org, etc). This then requires that every public suffix domain should >insert a new _dmarc TXT record. Because >many cctlds are bureaucratic and complicate, adoption for this will be >somewhat unpredictable.
No, that's not what RFC 9989 says. The psd=y/n tags are expected to be rare. In the usual case where the tree walk doesn't find either, the Organizational domain is the highest level in the tree that has a _dmarc record, which in nearly every case will produce the same result as the former PSL check. You can publish psd=n to say "this is an org domain" or psd=y to say "the org domain is one level down from here", but again, those will be rare. See section 4.10 and particularly 4.10.2 of RFC 9989. R's, John PS: I'm pretty sure that if you asked the editors of the RFC, they would agree. _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
