Knowledgebase

The Mail app included with Windows 8 only supports IMAP, Exchange, Hotmail/Outlook.com, and Gmail accounts. If you select POP3, you'll be informed that Mail doesn't support POP.  You can get another mail app in the windows store (which may be your best bet once they start to be offered).  To use the Mail app with a POP3 email account, there's a workaround you can use.

While Mail itself doesn't support POP3 accounts, it does support Outlook.com and Gmail accounts. Both Outlook.com and Gmail have a built-in feature that fetches mail from a POP3 server and stores it in your webmail inbox. If you configure one of these services to access your POP3 account, you can add the webmail account to the Mail app.

To get started, visit Outlook.com or Gmail and create an account if you don't already have one. Log into your account, click the gear icon at the top-right corner of either Outlook.com or Gmail, and select the Settings option.

Outlook.com

• click the Sending/receiving email from other accounts link
• click the Add an email account link

Gmail

• click the Accounts and Import tab
• click the Add a POP3 mail account you own link

Continue through either process and add your POP3 account details.  After you're done, Outlook.com or Gmail will automatically fetch new email and place it in your webmail inbox.

Add Your Outlook.com or Gmail Account

• Go into the Windows 8 Mail app and open the Settings charm.
• Select the Accounts option and tap or click Add an Account.
• Select Outlook or Google (whichever type of account you used above) and sign into the account with your username and password.
• The Mail app will now display the mail from your POP3 account, which is fetched by your Outlook or Gmail accounts. You'll see new emails appear on the Start screen.

Sending Mail

Unfortunately, this solution doesn't give you any way to send email from the POP3 address. You can send emails from your POP3 account from the Outlook.com or Gmail interface, but not from within the Mail app. To get around this, you can read your email in the modern Mail app and use a separate interface to reply to and send emails (either a desktop email program like Outlook or the Outlook.com or Gmail websites). You could also reply to people from within the Mail app - recipients will see mail as coming from your @outlook.com or @gmail.com email address, however. Make sure they expect emails coming from that address.