In addition to showing more types of information in your email listing, columns offer you a one-click way to sort messages by one particular piece of data. Note: Outlook 2010 will "remember" your email column fields and view settings on a folder-by-folder basis, so make sure to first navigate to the folder you actually want to customize!

Tip: to select multiple columns, hold down "Ctrl" (the control key) and click on one field after the other. To select all fields, click on the first and press Shift+End.