Re: [dmarc-ietf] ARC questions
John Levine <johnl@taugh.com> Tue, 24 November 2020 02:04 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 6234D3A0E8A for <dmarc@ietfa.amsl.com>; Mon, 23 Nov 2020 18:04:59 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 0.049
X-Spam-Level:
X-Spam-Status: No, score=0.049 tagged_above=-999 required=5 tests=[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=HbkX8cBg; dkim=pass (2048-bit key) header.d=taugh.com header.b=Voj4mi7Q
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 QK8BVzant4EY for <dmarc@ietfa.amsl.com>; Mon, 23 Nov 2020 18:04:57 -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 3CD203A0E88 for <dmarc@ietf.org>; Mon, 23 Nov 2020 18:04:56 -0800 (PST)
Received: (qmail 53558 invoked from network); 24 Nov 2020 02:04:54 -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=d131.5fbc6a46.k2011; bh=GMwj+/EMbT3eNwIZBrXuGbi9JZskwOSrvaeaV6womxU=; b=HbkX8cBgzaCteyE+X9Yd3Eg8CCWjsNkszP60hJzu/IvBZJaCMep4iVYCFXV4eV2iSpkbnkqQ9qhFNBBs8XYxm3bpG2NOXNaiYUV6IHZY2QX7ZF9CSPDPmkPFUqjDeruwxCLeEu4J/ojKCDVgYPJI9qvQA9272x5kDh7Ftyg4RD3+LdxeLKpdJ9/3rVWsyeI/twUqAn8B7tleyWxxNPxLJet3khTxCH1xXpjnhaGFZYs4r6L1y0zMuC03sDMwXHdtcS+civqPA5elwr/OZpwLL1Gy65kYXjMAq/YKMs2q9knlfdyy2BvFn+HsEbMavHJ7XNZdBowBerz9oHr9fUaHBA==
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=d131.5fbc6a46.k2011; bh=GMwj+/EMbT3eNwIZBrXuGbi9JZskwOSrvaeaV6womxU=; b=Voj4mi7QMSbs7/SUPMPfnqECw6QbrO4wyORPhSjCHHSrTqH4mpZiJ15MhK56scbLKXV3C+92q9xcOPW9cfrBCBA7QXq+ssLzBN+TO5jeoYi5b3fj/xLvD1p0DTBz421eVO4Qk716siqIyzBu0dQMMuMo/2eWZK8XEdomqlu0Tl3tGFzP+7EFtrdt02uC6qEFGrKvn+zbt5HiVhJ4LV1hlV5bj/mNtbyLUF0DqR3eysnjLOsgwNizcEhAqPv7hRV7uYFGNW5gRtb3oBFBDNthYhcoRgF2VgYkbVFMk6lFa0NijIzNRpLkeYGw6xXe78WCvFWG8HoFikZu39jBLIfIFQ==
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; 24 Nov 2020 02:04:54 -0000
Received: by ary.qy (Postfix, from userid 501) id AFDC027CE5C8; Mon, 23 Nov 2020 21:04:53 -0500 (EST)
Date: Mon, 23 Nov 2020 21:04:53 -0500
Message-Id: <20201124020453.AFDC027CE5C8@ary.qy>
From: John Levine <johnl@taugh.com>
To: dmarc@ietf.org
Cc: mike@mtcc.com
In-Reply-To: <e8e1d300-fbe7-6d10-c15f-30c29ab74237@mtcc.com>
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/P5EiAACwOIFcJ_ovf2q0N-VQVGs>
Subject: Re: [dmarc-ietf] ARC questions
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: Tue, 24 Nov 2020 02:04:59 -0000
In article <e8e1d300-fbe7-6d10-c15f-30c29ab74237@mtcc.com> you write: >What I'm struggling to understand is what having authenticated auth-res >from a previous hop helps. this is what i found: See some of the previous messages. My usual example is a mailing list message that fails DMARC at the final recipient but passed DMARC (as recorded in AAR) when it arrived at the list. This lets the final recipient distinguish between real messages from subscribers and mail from spambots that happened to scrape both the list address and some subscribers' address and sends mail to one pretending to be from the other. (That definitely happens, I've seen it on lists I'm on.) I agree that the ARC document does not do a great job of explaining that. >It would be kind of nice to understand what gap ARC actually plugs and >why it's important if you ask me. Also: there seem to be a lot of ways >to achieve this, but this one is probably the most complicated one that >I can envision. If you want to pass the A-R results through multiple rounds of forwarding, you can't do much less. R's, John
- [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John Levine
- Re: [dmarc-ietf] ARC questions John Levine
- Re: [dmarc-ietf] ARC questions Kurt Andersen (b)
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Douglas E. Foster
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Douglas E. Foster
- Re: [dmarc-ietf] ARC questions Joseph Brennan
- Re: [dmarc-ietf] ARC questions Todd Herr
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions Doug Foster
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions Todd Herr
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John Levine
- Re: [dmarc-ietf] ARC questions John Levine
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Dave Crocker
- Re: [dmarc-ietf] ARC questions John Levine
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Seth Blank
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Douglas Foster
- Re: [dmarc-ietf] ARC questions Murray S. Kucherawy
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Murray S. Kucherawy
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Murray S. Kucherawy
- Re: [dmarc-ietf] ARC questions Alessandro Vesely
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John Levine
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions John R Levine
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Michael Thomas
- Re: [dmarc-ietf] ARC questions Benny Pedersen
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Brandon Long
- Re: [dmarc-ietf] ARC questions Michael Thomas