Re: [dmarc-ietf] I-D Action: draft-ietf-dmarc-psd-03.txt

Seth Blank <seth@sethblank.com> Thu, 09 May 2019 17:35 UTC

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From: Seth Blank <seth@sethblank.com>
Date: Thu, 9 May 2019 10:35:28 -0700
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To: IETF DMARC WG <dmarc@ietf.org>
Cc: Scott Kitterman <sklist@kitterman.com>
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Subject: Re: [dmarc-ietf] I-D Action: draft-ietf-dmarc-psd-03.txt
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On Thu, May 9, 2019 at 9:39 AM Scott Kitterman <sklist@kitterman.com> wrote:

> In theory, I agree, but in practice, I think the new MUST NOT is a great
> change to promote implementation simplicity.


This increases complexity. With this normative requirement, we're adding a
third lookup that behaves differently than the previous two. This
complicates the experiment and solidifies a (good) policy consideration
normatively.


> > Speaking of which, with the normative MUST NOT that's been added, now 4.1
> > no longer makes any sense.
>
> Only if you assume that there are no privacy risks associated with
> aggregate
> reports, which I don't believe is accurate.  I certainly wrote 4.1 on the
> assumption that it was mostly about aggregate reports, since failure
> reports
> are not commonly sent.
>

The first bullet of 4.1 is incorrect if RUF is MUST NOT for PSD.

I thought I'd done that in Appendix A.  Please review and provide specific
> recommendations as I don't really know how to address this general comment.
>

You're absolutely right, you did.

I do, however, think there's more to the PSD experiment than just deciding
where a PSD list should live - the crucial bit is if this actually
addresses and demonstrates value (i.e. stops spoofed email) for the use
cases discussed in Section 1.