Re: [dmarc-ietf] Ratchets - Disallow PCT 1-99

Dave Crocker <dcrocker@gmail.com> Wed, 21 July 2021 17:24 UTC

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To: Laura Atkins <laura@wordtothewise.com>, IETF DMARC WG <dmarc@ietf.org>
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From: Dave Crocker <dcrocker@gmail.com>
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Date: Wed, 21 Jul 2021 10:24:35 -0700
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Subject: Re: [dmarc-ietf] Ratchets - Disallow PCT 1-99
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On 7/21/2021 1:28 AM, Laura Atkins wrote:
> This is going to cause difficulties in deployment for a lot of 
> companies and domains. Experience tells us that p=quarantine pct=0 
> detects forwarders and other types systems that modify and break DMARC 
> authentication. These systems are undetectable when p=none is in place. 

How is this 'detection' actually used?  That is, what is then done 
differently?


On 7/21/2021 10:19 AM, John Levine wrote:
> I suppose we could leave pct=0 as a hint to forwarders to turn on their DMARC evasion hacks.

Why doesn't seeing DMARC as seeing that it isn't p=none outght to 
suffice for that?


d/

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Dave Crocker
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