Re: [dmarc-ietf] Ticket #39 - remove p=quarantine

Alessandro Vesely <vesely@tana.it> Thu, 10 December 2020 08:55 UTC

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From: Alessandro Vesely <vesely@tana.it>
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Subject: Re: [dmarc-ietf] Ticket #39 - remove p=quarantine
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On Thu 10/Dec/2020 02:23:10 +0100 Michael Thomas wrote:
> On 12/9/20 4:04 PM, Brandon Long wrote:
>>
>> When you switch to p=quarantine pct=0, no one should apply quarantine (so 
>> it's equivalent to p=none), but Groups will start rewriting, thereby removing 
>> all of those failures from your reports.  Yes, you won't see those messages 
>> in the reports at all anymore because they are no longer using your domain.


There is a reporting feature of mlm-transform that might be worth considering 
apart from any indirect mailflow revival.  By adding an Original-From: header 
field —a copy of From: on the first relay— a domain owner can ask to receive 
aggregate reports even if From: was rewritten by a MLM.


> Is that what's going on with some of the messages I see on this list? That 
> seems pretty awful from a security standpoint. Basically you're engineering a 
> lookalike From address attack. The one big disappointment from my standpoint is 
> that MUA's don't seem to be using auth-res, etc, to do some basic annotation. 
> At least Thunderbird.


You need to install DKIM Verifier[*].  It reads A-R and displays some results.


Best
Ale
-- 

[*] https://addons.thunderbird.net/en-US/thunderbird/addon/dkim-verifier/