Based on the number of questions from Outlook users asking about POP3 support in Windows 8, it's clear there is a lot of confusion about Windows 8's lack of POP3 support.
"No POP3 support" begins and end with the Windows Mail app.
The Windows Mail app that you see on the Start screen does not support POP3 accounts.
If you are using the Windows 8 Mail app, you need to use accounts that support IMAP or ExchangeActiveSync email.
If your email account doesn't support IMAP or ActiveSync, you can configure an Outlook.com account to collect your mail, then use EAS to view it in the Windows Mail app.
Any email client that you install on the Windows 8 desktop, including Outlook, Live Mail Essentials, and Thunderbird, can use POP3 accounts. Windows 8 does not block POP3 services or ports.
Some of the confusion may result from the problems many users have connecting to their email accounts. In most cases, this is the result of the Windows firewall or other security software blocking Outlook or the port. In a few cases the user needs to adjust the timeout setting in the account or on their router. But in all cases, it's not because Windows 8 does not support POP3.
POP3 support was not included in the Windows Mail app because IMAP and ExchangeActiveSync sync the contents of the mailbox to the computer, generally giving the user a better experience when the mailbox is accessed from more than one computer. Changes sync back to the server - read state, deleted items, replies, sent items - so all computers are identical. While this may be less important with desktop computers, if you have Surface or other tablet device, keeping the mail on the server and syncing to all computers is convenient.