Receiving duplicate copies of an email message is a rather common problem that can occur while using a POP3 email client like Outlook. Beyond incorrect rule settings, there are multiple possible reasons why this can occur. The Microsoft Outlook executable is not limited to only one running instance. If multiple instances are running, duplicate requests to your POP3 server may result in downloading the same message twice. In other cases, leaving a copy of the message on the server or having two POP3 accounts for the same profile may cause you to receive the same message more than once. Writer Bio
