POP3 UE monitor not deleting emails

Hi there.

I'm troubleshooting a problem with our POP3/IMAP UE monitors and discovered that the POP3 monitor isn't deleting all the emails.  I have two questions about that.

1.  Can I clear out the mailbox without causing issues?

2.  What could be causing the monitor to not delete the messages from the server?

The server in question is an exchange 2010 server and SAM is at version 5.0.0.

Thanks,

Justin H.