On Tue, 18 May 2004 Valdis.Kletnieks@vt.edu wrote: : > Don't know about hotmail, but AOL is working on this. You might want to : > check out that SPAM-L list, if this is something you are interested in. : : Other than knowing that it's a good idea s/a good idea/an emerging requirement/ (and for one definition of the idea, s/a good idea/a soon-to-be RFC "MUST"/) : if you can do it, s/can do it/wish to send mail, or at least DSNs, to most of the 'net soon/ : but sometimes not doable with the resources at hand, s/.*// Those of us under a deluge of virus bounce spew just don't care anymore. If you don't reject at SMTP time, you're now a major part of the problem. (As a straw example, I happen to block, on a personal 12 user domain, almost 20k bounce spew attempts per day. That's simply untenable anymore.) : > Once AOL starts doing it -- you can bet they will be one of the ones : > blocking on it. : : That's going to pretty much torpedo the concept of secondary MX's. And what's the gain of secondary MX's that don't have access to a valid address list? Ever since the advent of globally deployed, permanently connected sending MX's, offsite secondary MX machines have become moot. SMTP mandates that a missed connection is equivalent to a 4xx error, in that the sender is to retry delivery later. That obviates any need for an offsite secondary MX in today's world. Unauditable SMTP transport -- that is, SMTP where neither the sender nor recipient values are verifiable -- is no longer a workable solution. The problems with that model are reaching critical mass, and if you don't think it's a problem now, just trust me; you'll be a believer soon enough. -- -- Todd Vierling <tv@duh.org> <tv@pobox.com>