Just got spammed with an email pretending to be an MS Critical update
for a vulnerability in Outhouse. A quick look at the headers:
FYI though it looked convincing.

Received: from 212.227.63.57 ([212.227.63.57]
helo=s137553944.websitehome.co.uk)
* by xxxxxxxxx ; 26 Jun 07 17:54:18 -0000
Received: from [127.0.0.1] (helo=infongd7634)
********by s137553944.websitehome.co.uk with smtp (Exim 3.35 #1)
********id 1I3FF3-0000oj-00
********for xxxxxxxxxx; Tue, 26 Jun 2007 19:54:17 +0200
Received: from user (see sender-info)
********by infongd7634.rtr.kundenserver.de with local; Tue, 26 Jun 2007
19:54:17 +0200
X-Sender-Info: 137553926@infongd7634
Date: Tue, 26 Jun 2007 19:54:17 +0200
Precedence: bulk
To: xxxxxxxxxxxxxxxx
Subject: Microsoft Security Bulletin MS07-0065 - Critical Update
From: "Microsoft Corp."<update@microsoft.com>
Content-Type: text/html;
* charset=iso-8859-1
Message-Id: <E1I3FF3-0000oj-00@s137553944.websitehome.co.uk>
X-PMFLAGS: 33555072 0 1 Y00BF1.CNM
X-UID: 34230
X-Length: 8379
Status: RO
X-Status: RC
X-KMail-EncryptionState:
X-KMail-SignatureState:
X-KMail-MDN-Sent: