Douglas Otis wrote (2007-07-25 on the DKIM list): > At this point in time, it should be rather rare for incoming SMTP > servers to depended upon a AAAA record for locating their servers. > The DKIM WG should push to have A or AAAA record discovery > deprecated. Deprecating address record discovery techniques will > eventually simplify where policy needs to be published. At some > point in the future, not publishing an MX record for the originating > domain might cause a message to be rejected.
Hi, scanning old messages I saw that you said this more than once on the DKIM mailing list. I'm also aware that Meng Weng Wong and others proposed something in this direction on the SPF and MARID list back in 2004. It's also related to the expired "null-MX" I-D, and because of that it might affect various "NOMAIL" solutions (4408 "v=spf1 -all" and Phil's I-D.hallambaker-nomail). I'm not strictly against it, quite the contrary. *But* AFAIK it's not planned to remove the "A fallback" from 2821bis, in fact 2821bis will augment all discussions of A records with AAAA for IPv6 compatibility. If you and others feel that the no-MX fallback should be limited to IPv4 in 2821bis, as it arguably is in 2821, then please say so on the SMTP list. Fixing the SMTP spec. for IPv6-only senders is something between tricky and impossible, and your proposal could shift this task from impossible towards tricky. Frank _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html
