Re: [dmarc-ietf] Ticket #1 - SPF alignment

John Levine <johnl@taugh.com> Mon, 01 February 2021 23:11 UTC

Return-Path: <johnl@iecc.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 9A9773A158E for <dmarc@ietfa.amsl.com>; Mon, 1 Feb 2021 15:11:58 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.851
X-Spam-Level:
X-Spam-Status: No, score=-1.851 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=iecc.com header.b=Ek08h6tl; dkim=pass (2048-bit key) header.d=taugh.com header.b=u9Du2XVP
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 1qnFDz8qNeUj for <dmarc@ietfa.amsl.com>; Mon, 1 Feb 2021 15:11:57 -0800 (PST)
Received: from gal.iecc.com (gal.iecc.com [IPv6:2001:470:1f07:1126:0:43:6f73:7461]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id C77E63A157B for <dmarc@ietf.org>; Mon, 1 Feb 2021 15:11:56 -0800 (PST)
Received: (qmail 82671 invoked from network); 1 Feb 2021 23:11:55 -0000
DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=iecc.com; h=date:message-id:from:to:cc:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:cleverness; s=142ed.60188abb.k2102; bh=Ex9I6mWIMVNptGB0YXBTmdBl9JnEYv0IecQf7f9sOEo=; b=Ek08h6tlgcSUjYA3ZeZ5THbcHIwXMZpzvb12c6iWuEgYLNxQuz5Y41Kzr7Fx82txoK8CPzJizsLHO5UQU5X695peNsBNww6+jxltcJ/o1e2BjenUTWjCqax4z6u0yrMkvabHpZ7MYWYUnG1bbkCYx5RoaKjw316diKuQUGaeLRreRha4CKT5kuvjUA48pyyUZ/SPn4ykavJweGyMbBTgTy3nOdc+PxUBVDbQuu7lBwz1bQeGm5gTVLi3z3BUn+IU5rM/O4Zgb9FZo+cO5IswIzx/yxGhnr2FBFyjeTEBI7yD7bQwFRZFfu33BlazcgvakrRjhkOXxsQ+8U6g0ekADA==
DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=taugh.com; h=date:message-id:from:to:cc:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:cleverness; s=142ed.60188abb.k2102; bh=Ex9I6mWIMVNptGB0YXBTmdBl9JnEYv0IecQf7f9sOEo=; b=u9Du2XVPlgN2NWx0sGD6DjbHNVSxV85VQvtnl+tP6EBGQxm+/PJHx0wPSRGroCbMfYJ0Bg2zyQ4sEDHd/bFFcg9cAfDcSBcJhwawUWiNvCzMlvIOstyKpJ5svfiAeSzpDnEcUcLvDVNlqk1kVg1lkUjB/VYtrTyH+6CPS1Lq/RL/aK/EJGQKzFsYSaIILiZbn92W263qERdNhaFH4ZLlX4zU2vHvLF10NsrjGMSsdLO8qxiZCmmT/7fcOAv3qRGks4kSX/adhpnKb8BLc6HcwWga3b3PEUpkE236+26hrJmuEDa4oGWbMUk2uT98h2BgV8JyaympCX0GAOHa9I/I3A==
Received: from ary.qy ([IPv6:2001:470:1f07:1126::78:696d:6170]) by imap.iecc.com ([IPv6:2001:470:1f07:1126::78:696d:6170]) with ESMTPS (TLS1.2 ECDHE-RSA AES-256-GCM AEAD) via TCP6; 01 Feb 2021 23:11:55 -0000
Received: by ary.qy (Postfix, from userid 501) id DAE426D208E1; Mon, 1 Feb 2021 18:11:54 -0500 (EST)
Date: 1 Feb 2021 18:11:54 -0500
Message-Id: <20210201231154.DAE426D208E1@ary.qy>
From: "John Levine" <johnl@taugh.com>
To: dmarc@ietf.org
Cc: vesely@tana.it
In-Reply-To: <babf1538-5172-f101-d5e4-c4fa33dea495@tana.it>
Organization: Taughannock Networks
X-Headerized: yes
Cleverness: minimal
Mime-Version: 1.0
Content-type: text/plain; charset=utf-8
Content-transfer-encoding: 8bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/dmarc/g4TSorE6DOPXbVhx70KrPifjuq8>
Subject: Re: [dmarc-ietf] Ticket #1 - SPF alignment
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, 01 Feb 2021 23:12:03 -0000

In article <babf1538-5172-f101-d5e4-c4fa33dea495@tana.it> you write:
>On Mon 01/Feb/2021 01:10:01 +0100 Scott Kitterman wrote:
>> I think that we're well past learning anything new in this thread.
>> 
>> SPF is what it is (RFC 7208).  DMARC doesn't need to re-invent the protocol
>> (and shouldn't).  For any properly implemented SPF verifier, DMARC should be
>> able to consume the Mail From result.
>
>Perhaps Courier-MTA is not so properly implemented, but when mail from is empty 
>it just omits the corresponding Received-SPF: header field.

That's a peculiarity of Courier.  My MTA adds an SPF clause in the A-R header
whether or not there's a null bounce address.

>OTOH, properly implemented SPF verifiers could skip producing a Mail From 
>result if the helo identity was verified successfully.

No, they could not.  That's not what the SPF spec says.

>It makes sense to add a section that modifies RFC 7208.  See below.

Please, can we stop the Mission Gallop?

R's,
John