Hi all, My very strong opinion is that the zero-preference-MX rule must still stand, regardless of how to tackle the domain-owners' problem. It's law. It's also often useful, especially when the DNS administrator isn't handy and you want mail service on a single public host, especially on a temporary basis. (It's amusing to think that, now that MX records are the commonality for which a transition plan was provided for non-users when first introduced, spammers often don't spam hosts without them because of their near-universal ubiquity.)
It doesn't matter what itch needs to be scratched to make MX or DNS usage perfect; taking the rule away is _going to break compatibility with old clients_. And that's all. When MX records were introduced, we would never have dreamed of doing a thing like that. So why are we even contemplating it now? (I think I've caught up with all of the discussion so far, but please point me to anything if it's already been answered.) To address the problem that begs for the rule's removal, however: how about a fake MX that rejects everything as the draft-rfc2821-bis allows with the 554 code on connection opening? How about not minding that the sending host is the one with the problem, and not you (not nice, so it'd be good to sort it out)? How about using a known-nonexistent (EG: definitely.invalid) host as your MX target (has more bad effects than known behaviour but at least it works - and when the rules don't allow us to do better than that for now, that's all we can hope for)? This "MX 0 ." sounds good as well, because it only requires time for implementers to get the idea and implement it while it's a bit of bother in the meantime. So no, please don't drop that rule. It's very handy, anyway, even if it is an irritating little blister just yearning to be popped, both to make semantics and practice clean and current for DNS and SMTP. But we spent ages making the MX record what it is - a record for indicating the names and preferences of mail exchangers, with a known behaviour for absent MX records. Changing the meaning of MX from being just a preference list to an actual indicator of whether mail is wanted or not would not have made sense at the time, and I feel strongly that it still hasn't got even the slightest motive for doing so today when practical and long-term solutions that can work without breaking compatibility seem possible with the minimum of badness. Cheers, Sabahattin -- Sabahattin Gucukoglu <mail<at>sabahattin<dash>gucukoglu<dot>com> Address harvesters, snag this: [EMAIL PROTECTED] Phone: +44 20 88008915 Mobile: +44 7986 053399 http://sabahattin-gucukoglu.com/
