I think Robert is seeing the mail header at the top of the document. In Word 2003 and earlier, you could get this by clicking on the E-Mail button on the Standard toolbar, but Word 2007 seems to offer only Send to Mail Recipient (as Attachment),* so I'm
not sure how you'd get the actual mail header.
*Even the button labeled E-Mail in the Customize the Quick Access Toolbar (All Commands) represents FileSendAsAttachment.
Edit: There is a Send to Mail Recipient command that can be added to the QAT, and clicking it does add the mail header, and clicking it again, to turn it off, removes the header.