I seem to be experienceing the same problem. I have Outlook XP. Everything was running fine, then all of the sudden, when I press Send/Receive, I get an annoying message "The Operation Failed". I've added another account - same problem. Any ideas?
I have noticed that I can send my mail by going to Tools -->Send/Receive -->Send ALL, still no receive.
*****Update : Added a profile with the same pop info and it worked. Went into the default profile, deleted the accounts, rebooted, reinstalled and I can send and receive*****