Re: [dmarc-ietf] Ticket #1 - SPF alignment

Alessandro Vesely <vesely@tana.it> Wed, 09 December 2020 11:46 UTC

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From: Alessandro Vesely <vesely@tana.it>
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Date: Wed, 9 Dec 2020 12:46:41 +0100
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Subject: Re: [dmarc-ietf] Ticket #1 - SPF alignment
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On Mon 07/Dec/2020 23:13:44 +0100 John Levine wrote:
> In article <CABuGu1prNdJKP_-2yv7NbnbVH340D75PPxKmeDTHEd8qG+0RtQ@mail.gmail.com> you write:
>>> I have a slight preference for the first option.  HELO is too arbitrary in
>>> the protocol for me to put much value in using it in any of these systems.
>>
>>There's a bit of an implementation detail though. If one is relying on an
>>encapsulated ck_host() function then you may not know whether it checked
>>the HELO or the MAIL FROM. Imposing a requirement like this from DMARC
>>seems like it verges on a layering violation.
> 
> You should be able to look at the bounce address and if it's null,
> skip the SPF check.  No need to peek inside SPF for that.


That would discard most bounces, since many MTAs send them directly, without 
going through a signing filter.


Best
Ale
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