Re: [dmarc-ietf] Nonexistent Domain Policy was: Re: Working Group Last Call: draft-ietf-dmarc-psd

Seth Blank <> Wed, 17 July 2019 05:19 UTC

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From: Seth Blank <>
Date: Tue, 16 Jul 2019 22:18:50 -0700
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Subject: Re: [dmarc-ietf] Nonexistent Domain Policy was: Re: Working Group Last Call: draft-ietf-dmarc-psd
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As an individual-

On Tue, Jul 16, 2019 at 10:05 PM Scott Kitterman <>;

> Although a few people have suggested this, I think it would be a mistake
> because it would cause a gratuitous incompatibility with RFC 7468.

The people suggesting this are the people asking for np= in the first place.

> I think it is a desirable characteristic that the addition of np not
> disturb
> existing expectations.  If a recipient that is a participant in the
> experiment
> attempts to determine policy for a sub-domain without 'np', then the
> result
> should match what a non-participant gets.

I'm not certain this is desirable for PSD in the context of an experiment
around np=.

Specifically, the point of np= is for strict enforcement for non-existent
domains while the remainder of the zone gets its act together moving
registered domains to policies more strict than none. Since, a) nearly all
sp= policies in the world are set to "none", and b) sp= is meaningless at
the PSD level anyway, I concur that np= should default to p=.

Or put a different way, the tags serve very different use cases, and in the
wild, sp= will generally be none, whereas np= will generally be
reject/quarantine. p= is the the meaningful tie-breaker here at the PSD
level if no np= is set.

This (np='s default) should also be called out as part of the experiment
around np if the group doesn't reach consensus before WGLC ends tomorrow.