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

Seth Blank <> Thu, 09 May 2019 17:35 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 7617E12006A for <>; Thu, 9 May 2019 10:35:48 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id C3Id4GOsPUAe for <>; Thu, 9 May 2019 10:35:46 -0700 (PDT)
Received: from ( [IPv6:2607:f8b0:4864:20::230]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 2ABB612003E for <>; Thu, 9 May 2019 10:35:46 -0700 (PDT)
Received: by with SMTP id 143so2545586oii.4 for <>; Thu, 09 May 2019 10:35:46 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=1XS9KSDBdB0vJYfJMmAdbBDgVJy+wcMRFrT05bTZoxI=; b=KfFOwxQkldF4B8sebwROplyRITZHd6lq3tMhUThJTb2miwIxlHGEqbK64PVUVvns1m G4p3d5kqcb5Qe/q5UFOhkMfOZ9lamCZfKhqjlevT2xNiYcn6M3BYl3lrid2GrwW+ylQD jtBfF/FR3Z4YTJ+wBFYStExAhvemxLObXBtYa61XeSiU9cusLKbpxiexMOBKYHoJZ1lX 5ZPIoYdaafc+1nOiLjkdcSXg1r+9CgGZevgSXVxHdyaxbxqxGrQMmIKVnSsNBVagSH4+ GmAbGztTVwVoiv/McQc4zc7Umul2Gu3ezxjZB/SW5M6VhOUekRglZhxt7M67MMbPwHRd mAGA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=1XS9KSDBdB0vJYfJMmAdbBDgVJy+wcMRFrT05bTZoxI=; b=Zg8U7N87Ae/qGpHRpsk29JTeq2reJdDCwfCwT+gyAlgo0UTsslAGHIc/i6DlAMUAY3 uBCkM7GdkvqFJrbZatRj8zygWymx7PVI4Q3QLzD2yWw26YL/iNMCAiw73I7R3tp21lfT JnzhWE6SCJjNnSx8L8a69+/SIO10hEoX+frzp2h5s22LtIdpwATmHcjVA0fnmgzXQn+D ixBeviNCDK2HOTJKsiK15cGIexcuMGm+79MIViylSi7j7yDxWcecbvYkUnNq+N9eVXzB rChqVvpsiTOCtcuTswGORKs8ri9hAjQGTKNOCxX//sb+btswKlNUIurILxj+PwJiZT0K p6pA==
X-Gm-Message-State: APjAAAUA5zuRZ4Lp2bRkZaggh+kdI7fv07+Y4tZtf1tWoLSOj1QXdczI OSHlvf8miMnGFQcrsnQUwKRX8BE3K+ekdA1b8DnGDw+HtQU=
X-Google-Smtp-Source: APXvYqxCdBSGHofpdXPduZEXaAWaKGvpxM1ZSRBBGssXXKIaaNQXAgDF0DhFKVnuToFaOOOeu2s2iZlPRSCA3WPCsn0=
X-Received: by 2002:aca:378a:: with SMTP id e132mr2146524oia.171.1557423344715; Thu, 09 May 2019 10:35:44 -0700 (PDT)
MIME-Version: 1.0
References: <> <2699063.PiBShnsfcX@l5580> <> <12992594.LUNhQVcRDa@l5580>
In-Reply-To: <12992594.LUNhQVcRDa@l5580>
From: Seth Blank <>
Date: Thu, 9 May 2019 10:35:28 -0700
Message-ID: <>
Cc: Scott Kitterman <>
Content-Type: multipart/alternative; boundary="0000000000003a2639058877e1ba"
Archived-At: <>
Subject: Re: [dmarc-ietf] I-D Action: draft-ietf-dmarc-psd-03.txt
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Domain-based Message Authentication, Reporting, and Compliance \(DMARC\)" <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Thu, 09 May 2019 17:35:48 -0000

On Thu, May 9, 2019 at 9:39 AM Scott Kitterman <> 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

> > 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.