Re: [dmarc-ietf] Endless Loops with DKIM reports

Dave Crocker <dhc@dcrocker.net> Thu, 06 June 2019 07:03 UTC

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To: John Levine <johnl@taugh.com>, dmarc@ietf.org
References: <20190605200619.2ED512014FE9B7@ary.local>
From: Dave Crocker <dhc@dcrocker.net>
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Date: Thu, 06 Jun 2019 09:03:26 +0200
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Subject: Re: [dmarc-ietf] Endless Loops with DKIM reports
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On 6/5/2019 10:06 PM, John Levine wrote:
> In article <29174612-a051-8066-9dde-2afaf181ca0e@dcrocker.net> you write:
>> The high-level point I'm trying to make is that control messages -- such
>> as DMARC reports -- need to be handled in a fashion that works
>> automatically and at scale.  Since looping is a well-known problem for
>> such messages, they need to be generated and handled in a way that
>> prevents the problem.
> 
> Right.  you can give all the advice you want about sending stuff in
> ways that's intended to prevent responses, but since some people will
> always ignore your good advice, and any single party only controls one
> leg of the loop, the only unlateral way to limit the damage is rate
> limiti

Taking your note's plain language, you appear to be of the rather 
peculiar view that specifying standards doesn't matter, since people 
won't follow them.

Looping is a classic problem.  It has classic solutions.  Getting the 
details of one specified for this case is, of course, different from 
getting people to adopt it, but the start is with specifying it.

Having additional, ad hoc mechanisms for dealing with non-compliance is 
quite a separate matter.


> It's fine to tell people to use null bounce addresses and from:
> addresses that don't ask for dmarc reports, but you need to rate limit
> anyway.

I looked at the rest of this thread, to see where this point had already 
been made, since your note seems to have a tone implying it's an 
established point, but I couldn't find it.  So again, ad hoc mechanisms 
might also be useful, but they are separate.

d/

-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net