Re: [ietf-smtp] Is this a valid Message-ID header ?

Valdis Kl ē tnieks <> Fri, 06 March 2020 03:27 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 9E6383A1231 for <>; Thu, 5 Mar 2020 19:27:52 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.899
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 ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 4l7WehVfAiux for <>; Thu, 5 Mar 2020 19:27:51 -0800 (PST)
Received: from ( [IPv6:2607:b400:92:8400:0:33:fb76:806e]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id B6EB53A1230 for <>; Thu, 5 Mar 2020 19:27:50 -0800 (PST)
Received: from ( [IPv6:2607:b400:92:8300:0:7b:e2b1:6a29]) by (8.14.4/8.14.4) with ESMTP id 0263RnDj031975 for <>; Thu, 5 Mar 2020 22:27:49 -0500
Received: from ( []) by (8.14.7/8.14.7) with ESMTP id 0263RiG1002510 for <>; Thu, 5 Mar 2020 22:27:49 -0500
Received: by with SMTP id d2so592458qko.3 for <>; Thu, 05 Mar 2020 19:27:49 -0800 (PST)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:in-reply-to:references :mime-version:content-transfer-encoding:date:message-id; bh=VJrr2FC1yCHM3enVoPyl5P1ZOdONAcqpK034T1+e1ys=; b=HE8nMHR5th3z1ldzDh9LOUS8alE7sSJkVKstX0iyJWKQnVGuHRizehDDh7hJ3Zq+K/ 43EL0FHDCPxpGvU7YTYLVYik53R5uqyxLsA67Jdk0X367s86XzDXFOqT/pKNNPI7zW72 7KTZ+rH4D6kWiAMmTwiXii9QHi8eyftCgnGIZwXLOoGT5t/Bv1QGXyBglTvqlpoQ9z1u rD5Yczgo1+wda712IkqzfP+ywbLfeocLpk1jPYnUMB38jwdTZM7fRNi8kHnWf0Wige16 d9tgsHm6LS4u8LUOz1vOYdnE+RknNb6KsE6XmIDwxZGvmZ5D71H3gljRjW5inoZecXXp 0fuw==
X-Gm-Message-State: ANhLgQ2Y5nSk/o0ekino0l/axdz4/1r5bhnfmVdg/20XFXvI4uZu0gzW EfsiKdNC8OWGinASCj9yFgjheoXNrP/9g1imC92lFBbZnPw5URNWr5/0wV93HslVBOTvC5RM2mR qJ5/nRqQTJirTcgotAShcgg==
X-Received: by 2002:ac8:6055:: with SMTP id k21mr1253538qtm.242.1583465264230; Thu, 05 Mar 2020 19:27:44 -0800 (PST)
X-Google-Smtp-Source: =?utf-8?q?ADFU+vvVDUG04vsN65Kdi/r8pipYd0Viidv2TZGCXdtY?= =?utf-8?q?4EnC0rYH03MSylfbxodHN5WeliDNtRADnA=3D=3D?=
X-Received: by 2002:ac8:6055:: with SMTP id k21mr1253528qtm.242.1583465263887; Thu, 05 Mar 2020 19:27:43 -0800 (PST)
Received: from turing-police ([2601:5c0:c001:c9e1::359]) by with ESMTPSA id z20sm1665199qkj.26.2020. (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Mar 2020 19:27:42 -0800 (PST)
Sender: Valdis Kletnieks <>
From: "Valdis Kl=?utf-8?Q?=c4=93?=tnieks" <>
X-Google-Original-From: "Valdis Kl=?utf-8?Q?=c4=93?=tnieks" <>
X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.7+dev
To: "John Levine" <>
In-Reply-To: <20200305043414.0E7C515740C2@ary.qy>
References: <20200305043414.0E7C515740C2@ary.qy>
Mime-Version: 1.0
Content-Type: multipart/signed; boundary="==_Exmh_1583465260_11464P"; micalg=pgp-sha1; protocol="application/pgp-signature"
Content-Transfer-Encoding: 7bit
Date: Thu, 05 Mar 2020 22:27:40 -0500
Message-ID: <87055.1583465260@turing-police>
Archived-At: <>
Subject: Re: [ietf-smtp] Is this a valid Message-ID header ?
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Discussion of issues related to Simple Mail Transfer Protocol \(SMTP\) \[RFC 821, RFC 2821, RFC 5321\]" <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Fri, 06 Mar 2020 03:27:53 -0000

On 04 Mar 2020 23:34:13 -0500, "John Levine" said:
> I read IETF mailing lists on the IETF's IMAP server* and of late I've been
> seeing some awfully funky stuff.
> This is an actual Message-ID header in one of the messages in dnsop.
> Is that valid?  Even though the MIME decodes to a an ASCII message ID
> in the <string@domain> format, I think the answer is no.  That's not
> what RFC 5322 sec 3.6 allows.

I'll see your Message-ID, and raise you a... not even sure *what* to call it. :)

>From my collection of emails that give exmh indigestion:

% grep UTF-8 183
From: =?UTF-8?B?dGlwLWJvdCBmb3IgRGF2aWQgQnJvd24gPHRpcGJvdEB6eXRvci5jb20+?
To: =?UTF-8?B?bGludXgtdGlwLWNvbW1pdHNAdmdlci5rZXJuZWwub3Jn?
Subject: =?UTF-8?B?W3RpcDptbS9yZWFkb25seV0gQVJNL3Zkc286IE1hcmsgdGhlIHZEU08gY29kZSA=?=  =?UTF-8?B?cmVhZC1vbmx5IGFmdGVyIGluaXQ=?=
Git-Commit-ID: =?UTF-8?B?MTFiZjliODY1ODk4OTYxY2VlNjBhNDFjNDgzYzlmMjdlYzc2ZTEyZQ==?=
X-Mailer: =?UTF-8?B?dGlwLWdpdC1sb2ctZGFlbW9u?=
Robot-ID: =?UTF-8?B?PHRpcC1ib3QuZ2l0Lmtlcm5lbC5vcmc+?=
Robot-Unsubscribe: =?UTF-8?B?Q29udGFjdCA8bWFpbHRvOmhwYUBrZXJuZWwub3JnPiB0byBnZXQgYmxhY2tsaXM=?=  =?UTF-8?B?dGVkIGZyb20gdGhlc2UgZW1haWxz?=
MIME-Version: =?UTF-8?B?MS4w?=
Content-Transfer-Encoding: =?UTF-8?B?OGJpdA==?=
Content-Type: =?UTF-8?B?dGV4dC9wbGFpbjsgY2hhcnNldD1VVEYtOA==?=
Content-Disposition: =?UTF-8?B?aW5saW5l?=

Amazingly enough, this managed to collect 10 Received: headers, land in my
mailbox, and exmh *mostly* figured it out:

From: tip-bot for David Brown <>
Subject: [tip:mm/readonly] ARM/vdso: Mark the vDSO code   read-only after init
Git-commit-id: 11bf9b865898961cee60a41c483c9f27ec76e12e
X-mailer: tip-git-log-daemon
Robot-id: <>
Robot-unsubscribe: Contact <> to get blacklis  ted from these emails
Mime-version: 1.0
Content-transfer-encoding: 8bit
Content-type: text/plain; charset=UTF-8
Content-disposition: inline

But then finally gave up because it tried to use the undecoded content-type,
gave up, and tossed up a "save/print/don't decode MIME" dialog.

And yes, tip-bot got fixed quite quickly thereafter... :)