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Re: [dmarc-ietf] DMARC2 & SPF Dependency Removal

Barry Leiba <barryleiba@computer.org> Thu, 08 June 2023 20:35 UTC

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From: Barry Leiba <barryleiba@computer.org>
Date: Thu, 08 Jun 2023 21:35:24 +0100
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To: Dotzero <dotzero@gmail.com>
Cc: Tobias Herkula <tobias.herkula=401und1.de@dmarc.ietf.org>, "dmarc@ietf.org" <dmarc@ietf.org>
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Subject: Re: [dmarc-ietf] DMARC2 & SPF Dependency Removal
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> A sender using both SPF and DMARC will see a slight
> boost in validation rates due to increased resiliency when there are
> transient DNS failures and other problems.

Do you mean "both SPF and DKIM", perhaps?

I don't see how that makes sense: if there's a transient DNS failure,
then neither the SPF nor the DKIM (nor the DMARC) records can be
retrieved.

I also don't see how using an unreliable mechanism is a benefit.  It
demonstrably hurts validation rates related to relayed/forwarded mail,
and can cause *false* validations in cases of overly-broad SPF
configurations (as when a large provider that also hosts many spammers
is used).

Barry

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