My wife and I are experiencing the same problem with Live Mail 2012. She has Windows 10 and I have Windows 7.

In the pop3 account only (iinet.net.au). We regularly receive duplicate apparent email in the Inbox. If that email is opened a message states that no content can be found. The original message does have the content.

The POP3 settings include leaving email on the server for at least 5 days.

How can this be stopped?