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

Scott Kitterman <sklist@kitterman.com> Thu, 22 June 2023 13:55 UTC

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From: Scott Kitterman <sklist@kitterman.com>
To: dmarc@ietf.org
Date: Thu, 22 Jun 2023 09:54:17 -0400
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Subject: Re: [dmarc-ietf] easier DKIM, DMARC2 & SPF Dependency Removal
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My conclusion (it won't surprise you to learn) from this thread is precisely 
the opposite.  

In theory, DKIM is enough for DMARC (this was always true), but in practice it 
is not.

I don't think there's evidence of a systemic weakness in the protocol.  We've 
seen evidence of poor deployment of the protocol for SPF, but I think the 
solution is to fix that (see the separate thread on data hygiene).

Scott K

On Thursday, June 22, 2023 9:46:07 AM EDT Sebastiaan de Vos wrote:
> It's not easy to set a DKIM key, I can agree with that. I do think,
> Marty should have tested before sending, though.
> 
> None of this, however, solves the issue of SPF weakening the DMARC
> standard. The weakness in SPF is not incidental, but systematic. That is
> - independent of the numbers - the reason why I vote to have SPF removed
> from the DMARC standard.
> 
> On 22.06.23 15:31, Todd Herr wrote:
> > When we look at the numbers others have posted on the topic, and we
> > see a perhaps higher than expected percentage of DMARC passes that
> > relied on SPF only (or at least a higher than expected rate of DKIM
> > failures) I'd posit that many of those DKIM failures are due to the
> > challenges that Marty and people like them face with getting the key
> > published.