Microsoft Outlook Express is susceptible to a vulnerability which will allow javascript to be execute in the message window. Tested against Microsoft Outlook Express version 6.0.2800.1123 on Microsoft Windows XP SP2.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/33766/msoeJavascript.txt
Source: https://packetstormsecurity.com/files/33766/msoeJavascript.txt.html