Re-download messages from pop3 server

I have setup a pop3 account in mail. The option to remove messages from server is not checked so the messages are both on the client and server.

I deleted all messages from the client and now I want to re-download them from the server. The server has a web interface and I set all messages as unread however the client does not recognize them as new messages and does not download them.

Any idea how to re-download these messages without re-creating the account?