Outlook 2010 is pretty decent but it is following in the path of many other softwares that actually lose functionality as it matures. Outlook 2007 had a great feature where you could just put a username, password and email address in their respective boxes and it would automatically set it up. This has failed miserably in 2010.
Trying to set up a POP3 email repeatedly asks for a password and returns something about the server rejected the login info. If you copy your old 2007 settings exactly, it still fails.
Solution (for me): Click on repair and more settings. Under the outgoing server tab uncheck the first box so the options gray out. Also, don't require logon Secure Password Authentication.