I don't know if this is a bug in Echo or in the way OpenStackManager integrates with it, but I got this empty notification just now:
To: Catrope <roan@wikimedia.org>
Subject: New notification at Wikitech
X-PHP-Originating-Script: 0:UserMailer.php
From: MediaWiki Mail <noc@wikimedia.org>
Reply-To: No Reply <noc@wikimedia.org>
Date: Wed, 04 Sep 2013 19:03:04 +0000
Message-ID: <labswiki.522783e832fdd3.58527144@wikitech.wikimedia.org>
X-Mailer: MediaWiki mailer
MIME-Version: 1.0
Content-type: text/plain; charset=UTF-8
Content-transfer-encoding: 8bit
You have a new notification.
To control which emails we send you, check your preferences:
https://wikitech.wikimedia.org/wiki/Special:Preferences#mw-prefsection-echo
Duplicated by: T56521: Useless notification mail on Wikitech