Re: [dmarc-ietf] ARC vs reject

Michael Thomas <> Mon, 07 December 2020 19:25 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id B9D0F3A064E for <>; Mon, 7 Dec 2020 11:25:49 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.651
X-Spam-Status: No, score=-1.651 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.249, NICE_REPLY_A=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id fpg4tBqhD7WD for <>; Mon, 7 Dec 2020 11:25:48 -0800 (PST)
Received: from ( [IPv6:2607:f8b0:4864:20::535]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 935A13A064A for <>; Mon, 7 Dec 2020 11:25:48 -0800 (PST)
Received: by with SMTP id w16so9754032pga.9 for <>; Mon, 07 Dec 2020 11:25:48 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20150623; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-transfer-encoding:content-language; bh=xN2W8PDHs9mi6Je9UNcJohYlM9yz5MsF/9tmCoEWg9Q=; b=1YjMeNpphKSy1/Kl+qwao91Fd85Y0FiqbPi/v2ClZZMJgwIlz09msd75VXjHeAoMdO C9xjYTnAFFHkii+JUiLrwNfEBMwjNKjxQj6YNx0ir02IQgyVCop1AFd67RmVMdUeRaqq AeDl2o4EsEV/cEFD2eQ83rA/aQeRcNvIwzS1xi3MRejvvVApG8O/3q4J0DeGVCz1wCnH xMQx1BoG9phWkK8QHEble2L+1V4MS/bjnKbHlUo0J9voPNtKQld/em0YdJ5QCot5FflZ 4PVCUeawL/ReyRTGqh4/1dkO36SxqlYbn+vl7TP95/4ZyBhzVZSltR4SH15AeyhOb3tl vzhA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=xN2W8PDHs9mi6Je9UNcJohYlM9yz5MsF/9tmCoEWg9Q=; b=mSVLFBsjYHuq6tFAVrgH/ICGAfNoYANQb0sehC/iOxenWUBgfRh0CbZSXUBLjj3Ata ZR2vjsAiS1xMVoQf2C1qQeN1MsdkKCIDk34wZUHNKZ2yIZmQQHINvntCqTN+IvfhYCt0 xMmGLUqWcPn2r+pGEsCciUVznaRcdiWDjGGwDw4H3uU/rPywRHoHq+CfpxALhHtBVYa6 MnbAvtACF78fbezTEFzI9NZe97P1sV/0aLBaQugHlTwND0LExxWnX5hq+34Ga5ECDIjM Y0kDEqaeP9uDeXHZgDmoEvCphS5wmbSz3/jmFtYYBxv9Ghjmqvri7bvb7SpwhPK+gj41 9byg==
X-Gm-Message-State: AOAM5326XPWY+6LHB2q63w7bF8wDzC1G/QDZMroBVb46qdoE9EATWINT ARrIXG79G+shyLoM+M4kbuW3Na/fhX3w4A==
X-Google-Smtp-Source: ABdhPJzNNoSqE1k+9EroHHhPaFXzqutpKk6W+KpkoEa3dt8d3kP40ApG8e1yAlm8QFcKJQT57NPhWA==
X-Received: by 2002:a17:902:b209:b029:d8:e7a4:bf10 with SMTP id t9-20020a170902b209b02900d8e7a4bf10mr18073330plr.77.1607369147381; Mon, 07 Dec 2020 11:25:47 -0800 (PST)
Received: from mike-mac.lan ( []) by with ESMTPSA id g33sm13309281pgm.74.2020. for <> (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 07 Dec 2020 11:25:46 -0800 (PST)
References: <20201207191959.6D772292166A@ary.qy>
From: Michael Thomas <>
Message-ID: <>
Date: Mon, 7 Dec 2020 11:25:45 -0800
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.5.0
MIME-Version: 1.0
In-Reply-To: <20201207191959.6D772292166A@ary.qy>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Archived-At: <>
Subject: Re: [dmarc-ietf] ARC vs reject
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: Mon, 07 Dec 2020 19:25:50 -0000

On 12/7/20 11:19 AM, John Levine wrote:
> In article <> you write:
>>     Compared with the use of "l=" tag (Section 8.2 of [RFC6376]), the
>>     fact that footers are written in plain text ...
> They are?  Some are, some are added as MIME parts.
> We really need to keep in mind that there is a lot of list management
> software with a vast array of configuration options.

This is why we need actual numbers instead of anecdotes about the long 
tail. We know that there is no silver bullet. Mailing lists who are 
configured in a way that causes their traffic to not get delivered can 
be configured in a way that will. It's not our problem.