IETF Logo Mail Archive

Re: [dmarc-ietf] Signaling forwarders, not just MLMs

Alessandro Vesely <vesely@tana.it> Fri, 14 April 2023 11:48 UTC

Return-Path: <vesely@tana.it>
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 5B5DDC151B12 for <dmarc@ietfa.amsl.com>; Fri, 14 Apr 2023 04:48:24 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -7.098
X-Spam-Level:
X-Spam-Status: No, score=-7.098 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, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_HI=-5, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, URIBL_DBL_BLOCKED_OPENDNS=0.001, URIBL_ZEN_BLOCKED_OPENDNS=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=neutral reason="invalid (unsupported algorithm ed25519-sha256)" header.d=tana.it header.b="NKdTe/KD"; dkim=pass (1152-bit key) header.d=tana.it header.b="CmIgf29Z"
Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id abl3ljc0HSgq for <dmarc@ietfa.amsl.com>; Fri, 14 Apr 2023 04:48:20 -0700 (PDT)
Received: from wmail.tana.it (wmail.tana.it [94.198.96.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 4DD90C14CE52 for <dmarc@ietf.org>; Fri, 14 Apr 2023 04:48:18 -0700 (PDT)
DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=tana.it; s=epsilon; t=1681472893; bh=G1NSbU9q9CMDFKwAGYMQRUxjAqaF9zEy/iswVf13GbQ=; h=Author:Date:Subject:To:References:From:In-Reply-To; b=NKdTe/KDWtMdNlPdD2Ebrn5pGraPOvbA+ouKRFlT2szI9YDXvcmU6M6G92nwfyrUS qC0UHHpKUesTUR3rE4cAw==
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tana.it; s=delta; t=1681472893; bh=G1NSbU9q9CMDFKwAGYMQRUxjAqaF9zEy/iswVf13GbQ=; h=Date:Subject:To:References:From:In-Reply-To; b=CmIgf29ZZYvjzi3sS8H0OtleTvmJpGyCebvsVCQ0s/QsD6LLsWbfWtPjUoiGT7lr+ loId5hThLBx3P9UZ3EgmG6jvJXfjhVgiLjh9I4nVQJhABfC4/yBVXmomkH1FENyXbb 0YWJ2SUxgbOmv5XEU6u7TZmddn+3RbYEXuuTDU2fX5AILjCtfatuEq9W5KhvV
Original-Subject: Re: [dmarc-ietf] Signaling forwarders, not just MLMs
Author: Alessandro Vesely <vesely@tana.it>
Received: from [172.25.197.111] (pcale.tana [172.25.197.111]) (AUTH: CRAM-MD5 uXDGrn@SYT0/k, TLS: TLS1.3, 128bits, ECDHE_RSA_AES_128_GCM_SHA256) by wmail.tana.it with ESMTPSA id 00000000005DC083.0000000064393D7D.000002D3; Fri, 14 Apr 2023 13:48:13 +0200
Message-ID: <94c85dbe-e4ae-122f-4ac3-c10644050e2d@tana.it>
Date: Fri, 14 Apr 2023 13:48:13 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0
Content-Language: en-US, it-IT
To: dmarc@ietf.org
References: <CAL0qLwYbbLLq-qLg_Wnp5aFw_2my4UTZz3U3LjwbCmpMNdudfA@mail.gmail.com> <20230413151342.B96D0BF17F1F@ary.qy> <CALaySJKM5Kct0u0ekuEBS=DVQTXG_CiewpzNwVyPiAaQ9zx3VA@mail.gmail.com>
Authentication-Results: tana.it; auth=pass (details omitted)
From: Alessandro Vesely <vesely@tana.it>
In-Reply-To: <CALaySJKM5Kct0u0ekuEBS=DVQTXG_CiewpzNwVyPiAaQ9zx3VA@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"; format="flowed"
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/dmarc/uVjw2YQm-zi6nfkMdX6CteN7Cvg>
Subject: Re: [dmarc-ietf] Signaling forwarders, not just MLMs
X-BeenThere: dmarc@ietf.org
X-Mailman-Version: 2.1.39
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: Fri, 14 Apr 2023 11:48:24 -0000

On Thu 13/Apr/2023 17:21:30 +0200 Barry Leiba wrote:
>> Anyone who does forwarding is damaged by DMARC because there are a lot of
>> people who do DMARC on the cheap with SPF only.
> 
> This brings up another issue, I think: that there should also be
> stronger advice that using DKIM is critical to DMARC reliability, and
> using SPF only, without DKIM, is strongly NOT RECOMMENDED.


+1.  However, properly used SPF implies extensive whitelisting.  It is 
relegated to Appendix D in RFC 7208, but it's the only one thing that makes SPF 
effective.

Best
Ale
--

v2.23.0 | Report a Bug | By Email