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

["Murray S. Kucherawy" <[e-mail]>]

On Thu, Mar 30, 2023 at 7:30 AM Douglas Foster <
[e-mail]> wrote:

> There is no interoperability problem.
>

How are you defining interoperability?

"p=reject" when used on domains that send non-transactional messages
disrupts interoperability of the email ecosystem in ways that are well
documented.  This collateral damage is not trivial.

There's no interoperability problem at the DMARC layer, sure.  But there's
a bigger story we need to consider.

An evaluator  has an unlimited right to block any incoming message for any
> reason.
>
Specifically, an evaluator has the right to block any message which he
> determines to be insufficiently authenticated.
>

An operator has every right to block DNS queries of types they don't like
or don't recognize.  The choice to do so by some firewalls was the source
of the problems behind the introduction of the SPF resource record.  That's
a pretty broad kind of disruption that I would claim also shouldn't have
been ignored or dismissed.  (See RFC 6686, Appendix A, for this story.)


> If a sender wants a message to be accepted, he carries the burden of
> earning the evaluator's trust.   He has no right to have his message
> delivered.
>
> [...]
>
> If an evaluator blocks a message that a user considers acceptable, that is
> a management issue between the user and the administrator.  It happens all
> the time, and it is resolved through normal support processes.
>

I don't think anyone's arguing that.  But does the receiver in your
scenario also have a right to impact the experiences of users not under
their control?  If we're going to argue that the receiver's rights are the
only thing that matter, we'd better be able to explain why the collateral
damage is justifiable.

-MSK, participating