very stange problem!!!
i'm using sbs2003 and pop3 connector to retrieve email for users. suddenly no new email was being recieved but we can still send out. messages were not being collcted by exchange as when i log directly into the mailbox using the hosts webmail they are all there. the event viewer is not showing any pop3 errors and i have it to log maximum. it shows that it connects to the remote mailserver and authenticates but returns There are 0 messages with a total of 0.
i installed ipopcon (thrid party pop connector) same result. cofigured outlook express on the server, when you send recieve it says no messages. i've diabled McAfee AV checked FW rules etc....
here is the strange thing. i configured outlook express on a server on a different network and it works!!!!