How do I view e-mail headers in Outlook 98/2000/2002/XP?

Highlight the message by single clicking on it. 

Right-click on the message and select Options.

At the bottom of the Message Options window, you will find the Internet headers section.

If you intend to send these to another person for review, you will need to copy the headers and paste them into a forward of the message. Right-click anywhere inside the Internet headers section, and choose Select All.

Click Close to close the Message Options window.

Click the Forward button.

Right-click inside the top portion of the message body, and select Paste.

Finally, fill in the To field and send your message.