IETF Logo Mail Archive

Re: [ietf-smtp] EHLO domain validation requirement in RFC 5321

Mark Andrews <marka@isc.org> Mon, 28 September 2020 23:11 UTC

Return-Path: <marka@isc.org>
X-Original-To: ietf-smtp@ietfa.amsl.com
Delivered-To: ietf-smtp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C9B523A145A for <ietf-smtp@ietfa.amsl.com>; Mon, 28 Sep 2020 16:11:27 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.899
X-Spam-Level:
X-Spam-Status: No, score=-1.899 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
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 VkUbufzuOR7T for <ietf-smtp@ietfa.amsl.com>; Mon, 28 Sep 2020 16:11:25 -0700 (PDT)
Received: from mx.pao1.isc.org (mx.pao1.isc.org [IPv6:2001:4f8:0:2::2b]) (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 368D03A0D3A for <ietf-smtp@ietf.org>; Mon, 28 Sep 2020 16:11:25 -0700 (PDT)
Received: from zmx1.isc.org (zmx1.isc.org [149.20.0.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx.pao1.isc.org (Postfix) with ESMTPS id 7BF353AB0CF; Mon, 28 Sep 2020 23:11:24 +0000 (UTC)
Received: from zmx1.isc.org (localhost [127.0.0.1]) by zmx1.isc.org (Postfix) with ESMTPS id 51009160069; Mon, 28 Sep 2020 23:11:24 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1]) by zmx1.isc.org (Postfix) with ESMTP id 3C37E16006D; Mon, 28 Sep 2020 23:11:24 +0000 (UTC)
Received: from zmx1.isc.org ([127.0.0.1]) by localhost (zmx1.isc.org [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id oACHMgkgp7L5; Mon, 28 Sep 2020 23:11:24 +0000 (UTC)
Received: from [172.30.42.67] (unknown [49.2.101.160]) by zmx1.isc.org (Postfix) with ESMTPSA id 595F5160069; Mon, 28 Sep 2020 23:11:23 +0000 (UTC)
Content-Type: text/plain; charset=utf-8
Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.7\))
From: Mark Andrews <marka@isc.org>
In-Reply-To: <1cdaa0a2-74eb-d7ea-ede7-df3e41c82bd@taugh.com>
Date: Tue, 29 Sep 2020 09:11:20 +1000
Cc: Keith Moore <moore@network-heretics.com>, ietf-smtp@ietf.org
Content-Transfer-Encoding: quoted-printable
Message-Id: <711F85E0-859E-4060-99F0-836F6A913347@isc.org>
References: <20200928221602.046CE22A35B3@ary.qy> <9d36f20f-3652-6b4e-b7a6-4a4b7d6fcd66@network-heretics.com> <1cdaa0a2-74eb-d7ea-ede7-df3e41c82bd@taugh.com>
To: John R Levine <johnl@taugh.com>
X-Mailer: Apple Mail (2.3445.9.7)
Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf-smtp/LmTH25iEg7Hel-VH2rAGrv72q8M>
Subject: Re: [ietf-smtp] EHLO domain validation requirement in RFC 5321
X-BeenThere: ietf-smtp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Discussion of issues related to Simple Mail Transfer Protocol \(SMTP\) \[RFC 821, RFC 2821, RFC 5321\]" <ietf-smtp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf-smtp>, <mailto:ietf-smtp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ietf-smtp/>
List-Post: <mailto:ietf-smtp@ietf.org>
List-Help: <mailto:ietf-smtp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf-smtp>, <mailto:ietf-smtp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 28 Sep 2020 23:11:28 -0000


> On 29 Sep 2020, at 08:44, John R Levine <johnl@taugh.com> wrote:
> 
>> (There are already some IPv6 only ISPs and I expect this will become more viable over time.   Should they have to set up IPv4 tunnels or ALGs for their "legitimate" customers so those customers can still send email to IPv4 servers?)
> 
> No, they need a fixed IPv4 address with an MX so people on IPv4 servers can send mail *to* them.  As we've said a few dozen times already, one mail server on one IPv4 address can handle a whole lot of mail for a whole lot of people, both inbound and outbound.
> 
> The usual word for one-way mail to which one cannot reply is "spam”.

And if you have a IPv6 address that is reachable it is not “spam”.  Out bound address do not have to
match in bound addresses.  Remember this is delivering email to legacy addresses who may well end up
having a smart dual-stacked host for outbound traffic to workaround not having IPv6.

> Regards,
> John Levine, johnl@taugh.com, Taughannock Networks, Trumansburg NY
> Please consider the environment before reading this e-mail. https://jl.ly_______________________________________________
> ietf-smtp mailing list
> ietf-smtp@ietf.org
> https://www.ietf.org/mailman/listinfo/ietf-smtp

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka@isc.org

v2.3.2 | Report a Bug | By Email