Re: [dmarc-ietf] Nonexistent Domain Policy was: Re: Working GroupLast Call: draft-ietf-dmarc-psd

Scott Kitterman <sklist@kitterman.com> Mon, 22 July 2019 10:44 UTC

Return-Path: <sklist@kitterman.com>
X-Original-To: dmarc@ietfa.amsl.com
Delivered-To: dmarc@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C53F212023C for <dmarc@ietfa.amsl.com>; Mon, 22 Jul 2019 03:44:22 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2
X-Spam-Level:
X-Spam-Status: No, score=-2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=neutral reason="invalid (unsupported algorithm ed25519-sha256)" header.d=kitterman.com header.b=gcZ4VTnR; dkim=pass (2048-bit key) header.d=kitterman.com header.b=mAgkWx7A
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ttRBOoaIWRwP for <dmarc@ietfa.amsl.com>; Mon, 22 Jul 2019 03:44:20 -0700 (PDT)
Received: from interserver.kitterman.com (interserver.kitterman.com [64.20.48.66]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 34A4F120220 for <dmarc@ietf.org>; Mon, 22 Jul 2019 03:44:20 -0700 (PDT)
Received: from interserver.kitterman.com (interserver.kitterman.com [IPv6:2604:a00:6:1039:225:90ff:feaa:b169]) by interserver.kitterman.com (Postfix) with ESMTPS id 3F229F80698; Mon, 22 Jul 2019 06:43:49 -0400 (EDT)
DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/simple; d=kitterman.com; i=@kitterman.com; q=dns/txt; s=201903e; t=1563792229; h=date : in-reply-to : references : mime-version : content-type : content-transfer-encoding : subject : to : from : message-id : from; bh=aQJknw78ZRY/7B4nF8a+fTS5USsCsWS1nU6w4TFq3o4=; b=gcZ4VTnRohdiGtp1HKvWkxrGwErMphkmXwNWxqHSK4UNXHGfATRRtcdq SnlQdOflsPyaCRViiVeldwwtM+4kAQ==
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kitterman.com; i=@kitterman.com; q=dns/txt; s=201903r; t=1563792229; h=date : in-reply-to : references : mime-version : content-type : content-transfer-encoding : subject : to : from : message-id : from; bh=aQJknw78ZRY/7B4nF8a+fTS5USsCsWS1nU6w4TFq3o4=; b=mAgkWx7Aey8MMqYJjX9BMGAeoLzwItQMrXmbDz3Aq/jMHhtYl+whxpND S+HoOVQEQNAEjUw3/fAW/XChq2Sb4zvrx6BabtSnQSZ4t1Nc4txYVvKeHQ mU7XWS8HjUJuRFSD+HRpehXhr73xttCvs15vSmcRGijhHOQt3dcxHP53/+ 5dDUeKCxyYzw5X4mIviCB7ukXPLB3psd4MaZ+qpXdYGT8AD35c4kKJ+5PI kWNbAx+NlAndG7yLO/UDSS3g9c2XZvykA4+LXkjRzNMfByx54SAPLNrSrp IrgzvnpxhDDnSULPpBNgB8SpY6/hdNRLO15JaE1b5AFYy+ZQUSu3bg==
Received: from [192.168.1.184] (static-72-81-252-22.bltmmd.fios.verizon.net [72.81.252.22]) by interserver.kitterman.com (Postfix) with ESMTPSA id 0F8A5F80618; Mon, 22 Jul 2019 06:43:49 -0400 (EDT)
Date: Mon, 22 Jul 2019 10:43:47 +0000
In-Reply-To: <83f0b1ffbf0c466eb3bc66e3510738f0@bayviewphysicians.com>
References: <CAL0qLwbbz_UhBLsURg=eXhRBC2g9OghiN==T9Uq9pFuLtd=b7w@mail.gmail.com> <1808303.aIhlromXIS@l5580> <CAD2i3WN42v0RHzu+2=+_mjX5kmxw6B-0F3-=bY-bTEsJM1qLvA@mail.gmail.com> <1692123.ljdY5SVR4M@l5580> <CAD2i3WPGWe8Z3av1Jua6sazsoStc7VTOLBve7psVo=K4VGTgig@mail.gmail.com> <D42C419C-F02E-4B5A-BB10-E8D49000349B@kitterman.com> <659dfb1f-dcb2-86ca-55a1-b3af6ce7ed1c@tana.it> <83f0b1ffbf0c466eb3bc66e3510738f0@bayviewphysicians.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
To: dmarc@ietf.org
From: Scott Kitterman <sklist@kitterman.com>
Message-ID: <5A081736-B654-4CFB-9551-6F750A1120A5@kitterman.com>
Archived-At: <https://mailarchive.ietf.org/arch/msg/dmarc/rhLWHS9YfnuAKDwUwnIPdJ8ljpg>
Subject: Re: [dmarc-ietf] Nonexistent Domain Policy was: Re: Working GroupLast Call: draft-ietf-dmarc-psd
X-BeenThere: dmarc@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Domain-based Message Authentication, Reporting, and Compliance \(DMARC\)" <dmarc.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dmarc>, <mailto:dmarc-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dmarc/>
List-Post: <mailto:dmarc@ietf.org>
List-Help: <mailto:dmarc-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dmarc>, <mailto:dmarc-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 22 Jul 2019 10:44:23 -0000


On July 22, 2019 4:31:40 AM UTC, "Douglas E. Foster" <fosterd@bayviewphysicians.com> wrote:
>About this paragraph:
>  
>>> The original pre-standardization version of this protocol included a
>  >> mandatory check of this nature. It was ultimately removed, as the
>>> method's error rate was too high without substantial manual tuning
>>> and heuristic work. There are indeed use cases this work needs to
>>> address where such a method would return a negative result about a
>>> domain for which reporting is desired, such as a registered domain
>>> name that never sends legitimate mail and thus has none of these
>>> records present in the DNS.
>  
>This section seems to give a free pass to senders who use non-existent 
>domains, as if such behavior had no impact on the risk posture of the 
>recipient. 
>It seems to say, "You can keep doing this, because so is everyone
>else."
>  
> I would think better language would be along the following lines:
>
>  
>
>"Senders SHOULD register all domains in DNS, as MTA operators MAY block
>
>messages that appear to come from non-existent domains.
>Developers of MTA filtering software SHOULD provide MTA operators with
>the 
>ability to block non-existent domains.
> If such ability is provided, the MTA filtering system MUST provide a 
>mechanism for overriding the filter rule for messages that are
>acceptable 
>to the recipient organization."
>  
>In short, the evaluation of whether manual tuning is worthwhile should
>be 
>left to the discretion of the MTA operator, based on his organization's
>risk tolerance and message characteristics.

I think that it is well outside the scope of this document to impose such a requirement.

Scott K