The mail client the comes with Windows 8 supports connecting to email servers using the IMAP protocol. However, it does NOT support email servers that use the older POP3 protocol.
However, if your email provider uses POP3, you have a couple of options open to you.
- Go to mail.live.com and add your POP3 account there. You will be able to create a new Outlook alias that you can use.
- Download a different email client such as Windows Live Essentials which supports POP3