Re: [dmarc-ietf] Definition of "value" in RFC8601

Damian Lukowski <rfc@arcsin.de> Wed, 01 April 2020 17:53 UTC

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From: Damian Lukowski <rfc@arcsin.de>
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Date: Wed, 1 Apr 2020 19:52:34 +0200
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Subject: Re: [dmarc-ietf] Definition of "value" in RFC8601
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>> This seems equivalent to
>>> authserv-id = sub-domain *("." sub-domain)
>>>    ; Where sub-domain is imported from 6531 for
>>>    ; any mail
> No, it's 6531 for EAI messages, and 5321 for ASCII messages.

If they are not equivalent, there must be a counterexample in which a
parser with

> authserv-id = sub-domain *("." sub-domain)
>    ; Where sub-domain is imported from 6531 for
>    ; any mail
and another parser with

> authserv-id = sub-domain *("." sub-domain)
>    ; Where sub-domain is imported from 5321 for ASCII mail
>    ; and 6531 for EAI mail.

, given identical input, disagree on the validity of the A-R header of
that input. Can you please show an example?

> EAI and ASCII mail are separate mail streams. The component that is
> parsing the A-R header had better know ahead of time whether your
> system is treating them separately.

Can you elaborate on this paragraph? Know what ahead of time? It sounds
like you agree, that the validity of an A-R header does depend on
external factors, not solely on the A-R content.