IETF Logo Mail Archive

Re: SMTP RFC: "MUST NOT" change or delete Received header

Eliot Lear <lear@cisco.com> Sat, 29 March 2014 09:51 UTC

Return-Path: <lear@cisco.com>
X-Original-To: ietf@ietfa.amsl.com
Delivered-To: ietf@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 6095E1A07AC for <ietf@ietfa.amsl.com>; Sat, 29 Mar 2014 02:51:34 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.511
X-Spam-Level:
X-Spam-Status: No, score=-14.511 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham
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 JwIUD_rkU2Ac for <ietf@ietfa.amsl.com>; Sat, 29 Mar 2014 02:51:32 -0700 (PDT)
Received: from mtv-iport-3.cisco.com (mtv-iport-3.cisco.com [173.36.130.14]) by ietfa.amsl.com (Postfix) with ESMTP id E17EC1A07AD for <ietf@ietf.org>; Sat, 29 Mar 2014 02:51:32 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=778; q=dns/txt; s=iport; t=1396086691; x=1397296291; h=message-id:date:from:mime-version:to:subject:references: in-reply-to:content-transfer-encoding; bh=ZGcy0dg1kJ6Uqg7E4AipSiYNc5n2Px2h8kvOlYLpaLY=; b=cAPlUEKNE7TeyR1dK1ccBjLfqWDyyhH5CKptMirEfQrCgNCK3XKHoNb7 J7jVNRNhJPbX6buwzR+U85abQeKyD82FcP77v+grclY6mgRrPaLLPaIX4 IpyuPNvsfsGIjbdWfgJTRSWCPRxNRTAI4RtA18gZR9zsPC64kiQ5bf99U I=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AhkFAGSWNlOrRDoI/2dsb2JhbABZgwY7g2G/b4EUFnSCJQEBAQQjVRELGAICBRYLAgIJAwIBAgFFBgEMCAEBh3QOrlqiZBeBKY0EAQFWgm+BSQEDmE6BM5ECgzE8gS4HFwY
X-IronPort-AV: E=Sophos;i="4.97,755,1389744000"; d="scan'208";a="106725645"
Received: from mtv-core-3.cisco.com ([171.68.58.8]) by mtv-iport-3.cisco.com with ESMTP; 29 Mar 2014 09:51:25 +0000
Received: from ELEAR-M-C3ZS.CISCO.COM ([10.61.211.143]) by mtv-core-3.cisco.com (8.14.5/8.14.5) with ESMTP id s2T9pN1p010439; Sat, 29 Mar 2014 09:51:24 GMT
Message-ID: <5336979B.6000102@cisco.com>
Date: Sat, 29 Mar 2014 10:51:23 +0100
From: Eliot Lear <lear@cisco.com>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:24.0) Gecko/20100101 Thunderbird/24.4.0
MIME-Version: 1.0
To: "Kevin M. Gallagher" <kevin@ageispolis.net>, ietf@ietf.org
Subject: Re: SMTP RFC: "MUST NOT" change or delete Received header
References: <mailman.1570.1395964793.2468.ietf@ietf.org> <53366F34.8050501@ageispolis.net>
In-Reply-To: <53366F34.8050501@ageispolis.net>
X-Enigmail-Version: 1.6
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Archived-At: http://mailarchive.ietf.org/arch/msg/ietf/c_mktZrQ_-wjq8pmzI9Z-xm_XOM
X-BeenThere: ietf@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: IETF-Discussion <ietf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf>, <mailto:ietf-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ietf/>
List-Post: <mailto:ietf@ietf.org>
List-Help: <mailto:ietf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf>, <mailto:ietf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 29 Mar 2014 09:51:34 -0000

Hi Kevin,

On 3/29/14, 7:59 AM, Kevin M. Gallagher wrote:
> What do people today think of the SMTP RFC's current requirement that
> mail programs and servers must not under any circumstances change or
> delete Received: headers? Is exposing sender IP addresses to any
> attacker who can view e-mail headers, for the purposes of preserving
> trace information, really worth it when weighed against considerations
> like security and privacy?
>
> http://tools.ietf.org/html/rfc5321#section-4.4
>

There is at least some value in retaining trace headers both for
debugging and anti-spam (mostly validating what one would expect to for
a given sender see), headers added by an MSA can entail privacy concerns
that (IMHO) outweigh debugging considerations.

Eliot

v2.23.0 | Report a Bug | By Email