>> Not to be cynical or anything, but regardless of what we decree, I >> think it's vanishingly unlikely that many systems on the public >> Internet* will accept mail from a domain with only an AAAA record. > I think it's vanishing unlikely that email will be useful at all, if spam > filter writers keep trashing mail based on such dubious criteria. Not to reignite the usual spam argument, but it is (unfortunately in this case) not 1988 or even 1998 any more. When upwards of 90% of all mail is spam, keeping mail usable is at least as dependent on limiting the spam that shows up in people's mailboxes as delivering the trickle of good mail. Real life spam filters use metrics and tune to the actual behavior of mailers. If most of the mail that comes from domains with AAAA and no MX is spam, they'll tune for that, and it won't be a mistake. For the forseeable future, most such mail will be from zombies, and it'll all be spam. R's, John _______________________________________________ IETF mailing list IETF@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf