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Re: [dmarc-ietf] Final, I hope, tweaks to the tree walk

John R Levine <johnl@taugh.com> Wed, 29 June 2022 14:12 UTC

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Date: Wed, 29 Jun 2022 10:12:20 -0400
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From: John R Levine <johnl@taugh.com>
To: Alessandro Vesely <vesely@tana.it>, dmarc@ietf.org
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Subject: Re: [dmarc-ietf] Final, I hope, tweaks to the tree walk
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On Wed, 29 Jun 2022, Alessandro Vesely wrote:
> Would you please show an example, realistic or not, where not stopping for 
> psd=y in step 2 leads to a useful result?

Keeping in mind that this is an arcane corner case that affects perhaps a 
few hundred of the 100,000 domains that are likely to publish DMARC 
records, and it doesn't matter in practice:

A site for aficionados of various kinds of pets:

_dmarc.petlovers.com p=reject psd=u
_dmarc.cats.petlovers.com psd=y
_dmarc.dogs.petlovers.com psd=y

A message from management:

From: felix@cats.petlovers.com
DKIM-Signature: d=petlovers.com
Subject: Dogs are bad
etc.

I'm not saying this is particularly likely, but it's no less likely than 
any other contrived psd=y scenario so I hope we can stop now and move on 
to something more important.

Regards,
John Levine, johnl@taugh.com, Taughannock Networks, Trumansburg NY
Please consider the environment before reading this e-mail. https://jl.ly

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