Re: [dmarc-ietf] Proposed text for p=reject and indirect mail flows

[Douglas Foster <[e-mail]>]

Suppose we use your language.  Some domains will still reject your advice,
so evaluators still need to apply intelligence to their disposition
decisions, if they care about  pleasing their account holders.

Mailing lists take a calculated risk by forwarding with changes.  Doing so
creates a trust problem between the list and the recipient's evaluator.
DMARC does not create the problem, it merely gives it visibility.

It is not the originator's job to solve the intermediary's trust problem,
especiallysince attempting to do so will facilitate the malicious conduct
of others.

Our job is to document the potential impact of decisions made by each
party: sender, forwarder, and evaluator.   It is not our job to decide
which party's interess must be sacrificed for the benefit of the other
participants

DF

On Wed, Mar 29, 2023, 10:15 AM Barry Leiba <[e-mail]> wrote:

> I'm very much against text such as this, as I think it encourages
> deployments that are contrary to interoperability and to the intent of
> p=reject.
>
> I contend that p=reject (as with the similar construct in the older ADSP)
> was intended for high-value domains and transactional mail, and that it was
> never intended for use in domains where general users send general email.
>
> I stand by the MUST NOT that I proposed.
>
> Barry
>
>
> On Wed, Mar 29, 2023 at 10:33 PM Todd Herr <todd.herr=
> [e-mail]> wrote:
>
>> On Tue, Mar 28, 2023 at 9:06 PM Pete Resnick <[e-mail]>
>> wrote:
>>
>>> If you agree that interoperability is increased, then I'd suggest that
>>> you actually do agree that the proposed text is appropriate.
>>>
>>>
>>> I don't know that I agree that interoperability is increased...
>>
>> I'm having trouble squaring proposed language that says "Domain owners
>> MUST NOT publish p=reject because it breaks interoperability" with the
>> following language from section 5.8:
>>
>> Mail Receivers **MAY** choose to accept email that fails the DMARC
>>
>> mechanism check even if the published Domain Owner Assessment Policy
>>
>> is "reject". In particular, because of the considerations discussed
>>
>> in [@!RFC7960], it is important that Mail Receivers **SHOULD NOT** reject
>>
>> messages solely because of a published policy of "reject", but that
>>
>> they apply other knowledge and analysis to avoid situations such as
>>
>> rejection of legitimate messages sent in ways that DMARC cannot
>> describe, harm to the operation of mailing lists, and similar.
>>
>>
>> It seems inconsistent to state with certainty that authorized mail will
>> be rejected due to authentication breakage when there is no requirement
>> that a reject policy be honored (and we have plenty of evidence that Mail
>> Receivers are following the 'SHOULD NOT reject messages' guidance).
>>
>> Language that would be more consistent in guidance to the domain owners
>> might look something like this:
>>
>> After careful analysis of the aggregate report data as described in
>> section 5.5.5
>>
>> (Collect and Analyze Reports), Domain Owners **MAY** choose to change
>> their
>> policy from 'none' to 'quarantine' or 'reject'. If, in the Domain
>> Owner's judgement,
>>
>> unauthorized and deceptive use of its domain name in the RFC5322.From
>> field puts
>>
>> at risk the trust it has built with its recipients, then it is
>> **RECOMMENDED** that
>>
>> the Domain Owner make use of the p and/or sp tags to set policy to
>> 'quarantine' or
>>
>> 'reject' for those streams most at risk of loss of trust.
>>
>>
>> If going that route, probably want to consider expanding on 5.5.5, too; I
>> need to think about it some more.
>>
>> --
>>
>> *Todd Herr * | Technical Director, Standards and Ecosystem
>> *e:* [e-mail]
>> *m:* 703.220.4153
>>
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