[whpalmer4]

Michael, you can just drag a message from the list in Mail and drop it in an OmniFocus note field for either a project or an action. You get a link which will open the Mail app (if necessary) and produce the linked message in a new window. It's identical to the "Original Message" link OmniFocus inserts if you clip the email with the Clip-o-Tron, and occupies negligible space in your database. Unfortunately, it will only work on your Mac, not on iPad/iPhone/iPod touch.