Re: [dmarc-ietf] ARC vs reject

Michael Thomas <> Sat, 05 December 2020 23:37 UTC

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To: Dave Crocker <>, John Levine <>,
References: <20201205231059.2BA23290EDCD@ary.qy> <> <>
From: Michael Thomas <>
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Date: Sat, 5 Dec 2020 15:37:10 -0800
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Subject: Re: [dmarc-ietf] ARC vs reject
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On 12/5/20 3:24 PM, Dave Crocker wrote:
> On 12/5/2020 3:15 PM, Michael Thomas wrote:
>> Can you keep your contempt for me off this list? This is not even 
>> responsive to what I wrote, and is nothing more than an ad hominem.
> Wow. It wasn't an ad hominem.

"You can say, no I am smarter than those guys and I REALLY REALLY mean 
it, but see 2) above."

This is really not about questioning my intelligence. eye roll. If I 
said the same thing to you, you'd be screaming bloody murder to the 
chairs to try to get me banned again.

> There is a fundamental flaw in the publisher of a dmarc record 
> thinking they have any rights or expectations about how a receiver 
> will choose to handle a dmarc failure.  It's fine for the publisher to 
> offer their own assessment of what the failure means to them.  It is 
> not fine for the publisher to pretend to tell the receiver what to do 
> about it.
> Even having a publisher's assessment be cast as 'advice' sets up the 
> false expectation that the receiver should believe and care about that 
> assessment.  Some might.  Others don't.  Talking about a receiver 
> 'overriding' DMARC policy exemplifies this false and inappropriate 
> expectation.
If the publisher of the DMARC record cannot accurately state its 
desires/policy, that is a deficiency in the protocol. Reject means I 
want you to reject it. It doesn't carve out exceptions. ARC is trying to 
carve out exceptions. If it wants an exception, the originating domain 
should have a say in whether it desires the receiving domain to carve 
out an exception one way or the other.