Message headers in Outlook 2003

Message headers are parts of an email that contain information about who it's going to, who sent it, what the reply address should be, what files are attached etc. In general they're handled completely by the email client (outlook in your case), any email you send to him should automatically have the headers attached (otherwise wouldn't get to him).

If he's trying to get you to forward a particular email to him, that's a little different, hitting the forward button will actually create a new mail containing the content of the original mail but it will have it's own headers, not the ones from the original mail. If this is what he wants you to do, there's two things you can do. One is to create a new mail to him, and drag-and-drop the mail he wants forwarded into it, this will add the original email, including it's headers, as an attachment to the mail. The other is to open the mail and in the toolbar go to 'View' and then 'Options', there'll be a box there with all the headers in it, copy these, then forward the original mail pasting these in somewhere.