Re: IETF Policy on dogfood consumption or avoidance - SMTP version
Viktor Dukhovni <ietf-dane@dukhovni.org> Tue, 17 December 2019 19:24 UTC
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Subject: Re: IETF Policy on dogfood consumption or avoidance - SMTP version
From: Viktor Dukhovni <ietf-dane@dukhovni.org>
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Date: Tue, 17 Dec 2019 14:24:43 -0500
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> On Dec 17, 2019, at 2:02 PM, Hector Santos <hsantos=40isdg.net@dmarc.ietf.org> wrote: > > But here is I see it: > > 1) Yes, everyone agree the response text needs to be fixed up, but > > 2) It is in fact a violation of RFC2821/5321 specification when a rejection is applied by a server to a perfectly valid ip-literal per specification, and It is not in fact. A receiving MTA can refuse your email for any reason. As a matter of RFC-compliance it MUST recognize address literals as valid syntax (which it did by returning a 550 rather than 500 or 501), but is then free to reject them on policy grounds. > 3) It lacks consistency in its operational decision on what Client Mail/Host Names are rejected or accepted. This is also not true. It consistently rejects address literals because doing so carries little risk of false positives (as already explained on the ietf-smtp list, where the more technical discussion belongs). "Real" MTAs use domain names. It is as simple as that. > If a rejection is going to apply to ip-literals, hence enforcing a FQDN, then at the very least, it should validate the FQDN. No, because enough "Real" MTAs use HELO domain names that don't map to their own IP address, or any address at all. So the risk of FPs is too high. There is no a priori discrimination here, it is all just based on what one can get away with to reduce spam without blocking a non-trivial volume of legitimate email. > The mail.ietg.org servers appears to accept any FQDN including a existing > FQDN which does not match the connecting IP address and a non-existing FQDNs: As they must for operational reasons. > Yet, it does not validate the FQDN. Why? Because, much as one might want to, too many "Real" MTAs (sending legitimate traffic) have FQDNs that would fail verification. -- Viktor.
- Re: IETF Policy on dogfood consumption or avoidan… Valdis Kl=?utf-8?Q?=c4=93?=tnieks
- IETF Policy on dogfood consumption or avoidance -… John C Klensin
- Re: IETF Policy on dogfood consumption or avoidan… Viktor Dukhovni
- Re: IETF Policy on dogfood consumption or avoidan… Randy Bush
- Re: IETF Policy on dogfood consumption or avoidan… John Levine
- Re: IETF Policy on dogfood consumption or avoidan… Viktor Dukhovni
- Re: IETF Policy on dogfood consumption or avoidan… Nick Hilliard
- Re: IETF Policy on dogfood consumption or avoidan… Keith Moore
- Re: IETF Policy on dogfood consumption or avoidan… John C Klensin
- Re: IETF Policy on dogfood consumption or avoidan… Viktor Dukhovni
- Re: IETF Policy on dogfood consumption or avoidan… Salz, Rich
- Re: IETF Policy on dogfood consumption or avoidan… Keith Moore
- Re: IETF Policy on dogfood consumption or avoidan… Valdis Kl=?utf-8?Q?=c4=93?=tnieks
- Re: IETF Policy on dogfood consumption or avoidan… John R Levine
- Re: IETF Policy on dogfood consumption or avoidan… Randy Bush
- Re: IETF Policy on dogfood consumption or avoidan… John C Klensin
- Re: IETF Policy on dogfood consumption or avoidan… Keith Moore
- Re: IETF Policy on dogfood consumption or avoidan… Nick Hilliard
- Re: IETF Policy on dogfood consumption or avoidan… S Moonesamy
- Re: IETF Policy on dogfood consumption or avoidan… Glen
- Re: IETF Policy on dogfood consumption or avoidan… Nick Hilliard
- Re: IETF Policy on dogfood consumption or avoidan… Phillip Hallam-Baker
- Re: IETF Policy on dogfood consumption or avoidan… Glen
- Re: IETF Policy on dogfood consumption or avoidan… Viktor Dukhovni
- Re: IETF Policy on dogfood consumption or avoidan… Andrew G. Malis
- Re: IETF Policy on dogfood consumption or avoidan… John C Klensin
- Re: IETF Policy on dogfood consumption or avoidan… Andrew G. Malis
- Re: IETF Policy on dogfood consumption or avoidan… Randy Bush
- Re: IETF Policy on dogfood consumption or avoidan… Jay Daley
- Re: IETF Policy on dogfood consumption or avoidan… Andrew G. Malis
- Re: IETF Policy on dogfood consumption or avoidan… Jay Daley
- Re: IETF Policy on dogfood consumption or avoidan… Rob Sayre
- Re: IETF Policy on dogfood consumption or avoidan… John C Klensin
- Re: IETF Policy on dogfood consumption or avoidan… Salz, Rich
- Re: IETF Policy on dogfood consumption or avoidan… Alissa Cooper
- Re: IETF Policy on dogfood consumption or avoidan… Jay Daley
- Re: IETF Policy on dogfood consumption or avoidan… Hector Santos
- Re: IETF Policy on dogfood consumption or avoidan… Viktor Dukhovni
- Re: IETF Policy on dogfood consumption or avoidan… Brian E Carpenter
- Re: [ietf-smtp] IETF Policy on dogfood consumptio… Hector Santos
- Re: [ietf-smtp] IETF Policy on dogfood consumptio… Salz, Rich
- Re: [ietf-smtp] IETF Policy on dogfood consumptio… Keith Moore
- Re: [ietf-smtp] the inedible parts of IETF dogfoo… John Levine
- Re: [ietf-smtp] the inedible parts of IETF dogfoo… Keith Moore
- Re: [ietf-smtp] the inedible parts of IETF dogfoo… George Michaelson
- Re: [ietf-smtp] IETF Policy on dogfood consumptio… Randy Bush
- Re: [ietf-smtp] IETF Policy on dogfood consumptio… Hector Santos
- Re: [ietf-smtp] IETF Policy on dogfood consumptio… Hector Santos
- Re: IETF Policy on dogfood consumption or avoidan… John C Klensin
- Re: IETF Policy on dogfood consumption or avoidan… Eliot Lear
- Re: IETF Policy on dogfood consumption or avoidan… Alissa Cooper
- Re: [ietf-smtp] epostage is still a bad idea, the… John R Levine
- Re: [ietf-smtp] IETF Policy on dogfood consumptio… Salz, Rich
- Re: [ietf-smtp] epostage is still a bad idea, the… Phillip Hallam-Baker
- Re: IETF Policy on dogfood consumption or avoidan… Keith Moore
- Re: IETF Policy on dogfood consumption or avoidan… Hector Santos
- Re: IETF Policy on dogfood consumption or avoidan… John C Klensin
- Re: IETF Policy on dogfood consumption or avoidan… Eliot Lear
- Re: IETF Policy on dogfood consumption or avoidan… Alessandro Vesely
- Re: IETF Policy on dogfood consumption or avoidan… Viktor Dukhovni
- Re: IETF Policy on dogfood consumption or avoidan… Eliot Lear
- Re: IETF Policy on dogfood consumption or avoidan… Hector Santos
- Re: [ietf-smtp] epostage is still a bad idea, the… Brandon Long
- Re: [ietf-smtp] epostage is still a bad idea, the… Phillip Hallam-Baker
- Re: IETF Policy on dogfood consumption or avoidan… Valdis Kl=?utf-8?Q?=c4=93?=tnieks
- Re: IETF Policy on dogfood consumption or avoidan… Hector Santos
- The dogfood discussion (was: Re: IETF Policy on d… John C Klensin
- Re: The dogfood discussion (was: Re: IETF Policy … Viktor Dukhovni
- Re: The dogfood discussion (was: Re: IETF Policy … Eliot Lear (elear)