Once you start filing your e-mail messages in folders, you'll notice that some folders get used more frequently than others. To make finding and filing go faster, move those frequently used folders to Favorite Folders.
To make a folder a favorite, drag it from Mail Folders to the Favorite Folders area of the Navigation Pane.
Note The folders stay in their original locations in your mailbox. The Favorite Folders area simply provides a quick and easy way for you to access them.