Re: [dmarc-ietf] Ticket #1 - SPF alignment
Jim Fenton <fenton@bluepopcorn.net> Sat, 30 January 2021 19:59 UTC
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From: Jim Fenton <fenton@bluepopcorn.net>
To: "Murray S. Kucherawy" <superuser@gmail.com>
Cc: Alessandro Vesely <vesely@tana.it>, IETF DMARC WG <dmarc@ietf.org>
Date: Sat, 30 Jan 2021 11:59:13 -0800
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Subject: Re: [dmarc-ietf] Ticket #1 - SPF alignment
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On 29 Jan 2021, at 12:30, Murray S. Kucherawy wrote: > On Fri, Jan 29, 2021 at 3:02 AM Alessandro Vesely <vesely@tana.it> > wrote: > >> I just run a quick test on my current folder. Out of 3879 messages I >> extracted >> 944 unique helo names. 721 of these matched the reverse lookup >> exactly. >> Out >> of the 223 remaining, 127 had an SPF pass for the helo identity >> anyway. >> So in >> 96 cases, roughly 10%, the helo name was indeed junk. Isn't the >> remaining >> ~90% >> something worth considering? The issue isn’t the existing use of HELO names, it’s how they could be (mis-)used. The fact that a message sender can put anything there makes HELO basically meaningless. > I am admittedly quite heavily biased against using the HELO/EHLO value > for > anything. I have simply never found value in it, probably because at > the > SMTP layer it's simply a value that gets logged or used in cute ways > in the > human-readable portion of SMTP. I seem to recall (but cannot seem to > find > at the moment) RFC 5321 saying you can't reject HELO/EHLO based on a > bogus > value, so it's even explicitly not useful to me. > > Even if it's not junk, there's pretty much always something else on > which > to hang a pass/fail decision about the apparent authenticity of a > message > that at least feels safer if not actually being more sound. Or put > another > way, if you present to me a DKIM-signed message with a MAIL FROM value > and > the only thing that passes is an SPF check against HELO, I'm mighty > skeptical. > > Anyway, I'll let consensus fall where it may. +1 to Murray’s comments. I realize that null MAIL FROM on bounce messages is a problem for SPF, but relying on HELO is not a reasonable substitute. -Jim
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- [dmarc-ietf] Ticket #1 - SPF alignment John R Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Murray S. Kucherawy
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Murray S. Kucherawy
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Dotzero
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Kurt Andersen (b)
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John R Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Todd Herr
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Todd Herr
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Murray S. Kucherawy
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Murray S. Kucherawy
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Murray S. Kucherawy
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Jim Fenton
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Jim Fenton
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John R Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Jim Fenton
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John R Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Michael Thomas
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John R Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Hector Santos
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Hector Santos
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John R Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Jim Fenton
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John R Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John R Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Dotzero
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Kurt Andersen (b)
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Dave Crocker
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Todd Herr
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John Levine
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Kurt Andersen (b)
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Dave Crocker
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Alessandro Vesely
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Douglas Foster
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Scott Kitterman
- Re: [dmarc-ietf] Ticket #1 - SPF alignment Seth Blank
- Re: [dmarc-ietf] Ticket #1 - SPF alignment John Levine