How to view the original message in Outlook

Check out this:

For the sake of not lose the information if the page is down:

Type “regedit”.
Hit Enter.
Go to HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Options\Mail.
- For Outlook 2003, go to HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Options\Mail.
Select Edit | New | DWord from the menu.
Type “SaveAllMIMENotJustHeaders”.
Hit Enter.
Double-click the newly created SaveAllMIMENotJustHeaders value.
Type “1”.
Click OK.
Close the registry editor.
Restart Outlook if it has been running.

The source of the message will appear under View → Options → internet headers.