nanog mailing list archives
Re: DNS question, null MX records
From: Paul Vixie <vixie () isc org>
Date: Thu, 17 Dec 2009 05:36:01 +0000
Douglas Otis <dotis () mail-abuse org> writes:
Agreed. But it will impact providers generating a large amount of bounce traffic, and some portion of spam sources that often start at lower priority MX records in an attempt to find backup servers without valid recipient information. In either case, this will not cause extraneous traffic to hit roots or ARPA.
if you're just trying to stop blowback from forged-source spam, and not trying to stop the spam itself, then some mechanism like an unreachable MX does seem called for. note that those approaches will cause queuing on the blowerbackers, rather than outright reject/die. other approaches that could cause outright reject/die would likely direct the blowback to the blowback postmasters, who are as innocent as the spam victims. i'm not sure there's a right way to do this in current SMTP. i used to think we could offer to verify that a piece of e-mail had come from us using some kind of semi-opaque H(message-id) scheme, but in studying it i found that as usual with spam the economic incentives are all backwards. -- Paul Vixie KI6YSY
Current thread:
- RE: DNS question, null MX records, (continued)
- RE: DNS question, null MX records Eric J Esslinger (Dec 15)
- Re: DNS question, null MX records Andy Davidson (Dec 15)
- Re: DNS question, null MX records Douglas Otis (Dec 15)
- Re: DNS question, null MX records Mark Andrews (Dec 15)
- Re: DNS question, null MX records Tony Finch (Dec 16)
- Re: DNS question, null MX records Douglas Otis (Dec 16)
- Re: DNS question, null MX records Joe Abley (Dec 16)
- Re: DNS question, null MX records Douglas Otis (Dec 16)
- Re: DNS question, null MX records Paul Vixie (Dec 16)
- Re: DNS question, null MX records Douglas Otis (Dec 16)
- Re: DNS question, null MX records Paul Vixie (Dec 16)
- RE: DNS question, null MX records Jay Mitchell (Dec 18)
- Re: DNS question, null MX records Douglas Otis (Dec 15)
- Re: DNS question, null MX records Tony Finch (Dec 17)
- Re: DNS question, null MX records Douglas Otis (Dec 17)
- Re: DNS question, null MX records James Hess (Dec 17)
- Re: DNS question, null MX records Mark Andrews (Dec 17)
- Re: DNS question, null MX records Tony Finch (Dec 18)
- Re: DNS question, null MX records *summary of on list and off list replies* Phil Vandry (Dec 15)