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

John Levine <johnl@taugh.com> Mon, 28 September 2020 22:16 UTC

Return-Path: <johnl@iecc.com>
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 DEAC33A1434 for <ietf-smtp@ietfa.amsl.com>; Mon, 28 Sep 2020 15:16:07 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.851
X-Spam-Level:
X-Spam-Status: No, score=-1.851 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, 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=BaAOp4AK; dkim=pass (2048-bit key) header.d=taugh.com header.b=MgCMaAgz
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 8nSVVR-jpIfk for <ietf-smtp@ietfa.amsl.com>; Mon, 28 Sep 2020 15:16:05 -0700 (PDT)
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 810273A1074 for <ietf-smtp@ietf.org>; Mon, 28 Sep 2020 15:16:05 -0700 (PDT)
Received: (qmail 24339 invoked from network); 28 Sep 2020 22:16:02 -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; s=5f11.5f7260a2.k2009; bh=/tnP9RJg/xf1XAxP2NTFiMZVzl6BC2a+MaF+ZJtbwlE=; b=BaAOp4AKDxn+CmCUcoKcyX5kgB8ZUxrcXnBzWTPMwkbMwOwQ0hjN8B6B83rgXHj6+7m5a1TotQ9Ho9jQs6QBGZ0MNO+gIu1rwNb9yqAT7kkZElAR0ipXVvnsHcwooCvkAxYULa5S4kzFkr6SjDLDb3tjfL76l+ltn4kV+NfrQOrnteOxkV5I0tby0QoVTV5shQeinG0QyzDGEqGz2/doauSuM+p2aDWSLUDOeldU5+Y5jthPBU95gPmyeC9F62zyke4NYA3zcBBsyCgVhI20acvVkcWpDsIQ605t6d2/tMHAwzS3RJDQ0gq/Wd76RXOoLfmIz73zYBElXA4X2WCfpg==
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; s=5f11.5f7260a2.k2009; bh=/tnP9RJg/xf1XAxP2NTFiMZVzl6BC2a+MaF+ZJtbwlE=; b=MgCMaAgzHN6GKjV6jUk778WIEsXID7yNBccMMzSkA+rvrn1mC0nfQ3kFWh2bebT78fIAefDmYburvp21crRj1tfMbZkdnbyciBCyGSvlVMplbrocryKd94NOBpBA83U4HqgRrOjFxhzB4mNiuw2cutYHExxQefSHy2zhA0mXdM5ozklWwxG4vGUtf/Bvw7m5/zFbg0XjkpJdafsYCVWo+Yb/RUoHinTmyzdHH0jfjhvtL90B8DwYAQdo7MdKP6JygnCs4Xmv6aUROnJTtMUM9EN6T1SJcNtAmMomQIMTGhfMDMymOI5t9WtyCz3Sy6n4PGMlraIBU3DUkbWLvrjqJA==
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; 28 Sep 2020 22:16:02 -0000
Received: by ary.qy (Postfix, from userid 501) id 046CE22A35B3; Mon, 28 Sep 2020 18:16:01 -0400 (EDT)
Date: 28 Sep 2020 18:16:01 -0400
Message-Id: <20200928221602.046CE22A35B3@ary.qy>
From: "John Levine" <johnl@taugh.com>
To: ietf-smtp@ietf.org
Cc: moore@network-heretics.com
In-Reply-To: <b47992c5-17dc-f461-c1cd-1e4277f52c00@network-heretics.com>
Organization: Taughannock Networks
X-Headerized: yes
Mime-Version: 1.0
Content-type: text/plain; charset=utf-8
Content-transfer-encoding: 8bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf-smtp/6vSTUDhKoQy7mY4nWOJw53xaqLI>
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 22:16:08 -0000

In article <b47992c5-17dc-f461-c1cd-1e4277f52c00@network-heretics.com> you write:
>On 9/28/20 10:27 AM, John Levine wrote:
>
>> Keith is asking us to expect that mail clients will move behind NAT64
>> even while their associated servers do not,
>
>No, I expect IPv4 to go away.   Gradually at first, and then much more 
>quickly.    Are people here really going to insist that operators have 
>to maintain IPv4 servers (or ALGs or whatever they need to maintain the 
>illusion that the client and server see the same source IP address?).   

I'm sorry but this is making less and less sense.

You appear to be saying there will be mail systems that need to send
mail to IPv4 systems, but will not have an IPv4 mail server so the
recipients can't reply to them.  Really?

If you do expect the recipients to be able to reply, why wouldn't the
inbound IPv4 mail server's address be the one it uses to send mail,
like it has for the past 40 years?

R's,
John