I've seen a mail plugin that can allow you to access hotmail, but never tried it.
POP and IMAP are both protocols for accessing email stored on the server. The difference between the two is that POP (Post Office Protocol) downloads the emails to your computer while IMAP (Internet Message Access Protocol) stores the messages on the server and only downloads the messages when you open them.
However, with most modern email applications it is difficult to tell the difference between the two. POP has the ability to leave a copy of the message on the server and IMAP message can be cached on your machine.