Are you positive that you receive email via POP3 on port 110? This way the POP3 traffic must be checked before the data reaches the email client so it works independently from the mail client used.
I tried windows live mail today because I want a client to check my live mail instead of logging onto the URL every time, am I right in assuming it's actually using http traffic to transfer these emails? It seems more like a mini web browser with a build in email client for optional pop3/imap accounts. Other than that it's quite a nice client.