A simple fix for the "Relay access denied" error message you might get when you try to send an email through your pop3 program and you are using an external smtp server for outgoing emails.

The simple fix is to make sure you are using checking the settings for Outgoing Server in a box that says that it requires authentication... and make sure you are clicking on "Use same settings as my incoming mail server" or "Log on using ID/pass" instead of accidentally clicking on "Log on to incoming mail server before sending mail."