From MAILER-DAEMON Sat Nov  7 09:58:19 2020
Date: 07 Nov 2020 09:58:19 +0100
From: Mail System Internal Data <MAILER-DAEMON@example.org>
Subject: DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA
Message-ID: <1604739106@example.org>
X-IMAP: 1604739499 0000000000
Status: RO

This text is part of the internal format of your mail folder, and is not
a real message.  It is created automatically by the mail system software.
If deleted, important folder data will be lost, and it will be re-created
with the data reset to initial values.

From microsoft@example.org Sat Nov  7 06:26:34 2020 +0100
Return-path: <microsoft@example.org>
Envelope-to: tpo@example.org
Delivery-date: Sat, 07 Nov 2020 06:26:34 +0100
Received: from hostie.example.org ([144.76.60.236] helo=example.org)
	by mta-host with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
	(Exim 4.94)
	(envelope-from <microsoft@example.org>)
	id 1kbGkE-00033B-0D
	for tpo@example.org; Sat, 07 Nov 2020 06:26:34 +0100
Received: (nullmailer pid 28609 invoked by uid 0);
	Sat, 07 Nov 2020 05:26:33 -0000
From: microsoft@example.org (some microsoft mail processing software)
To: tpo@example.org
Subject: Mail with newline in Message-Id
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin>
X-Cron-Env: <HOME=/root>
X-Cron-Env: <LOGNAME=root>
Date: Sat, 07 Nov 2020 06:26:33 +0100
Message-ID: <2732c0a646434835942d020ffffd20f5@GV0P278MB0002.CHEP278.PROD.OUTLOOK.COM>
Status: R
X-Status: 
X-Keywords:                  
X-UID: 1

I have seen emails from microsoft email software with
"folded" Message-IDs.

