In previous versions of Outlook, when you opened an email and selected File, then Save As, the program saved the message as a single Outlook mail file. That was nice, compact, and easy to transport.
It also was unreadable to computers that didn't' have Outlook installed.
To get around that, Outlook 2007 defaults to saving messages as .html files. Every computer can read one of those. Unfortunately, since the .html format doesn't support everything found in an email, even an html-formatted email, Outlook has to provide a folder with a few extra files. For the message to display properly, that folder must remain in the same location as the .html file.
So what should you do if compact, single-file messages are more important to you than universal compatibility? Select File, then Save As. In the Save As dialog box' "Save as type" pull-down menu, select Outlook Message Format. Then save the file.
Or you can simply drag the message from Outlook to a folder or to the desktop.