I have a customer who's emails are POP3 but are setup like an exchange account using a POP3 connector. I had a new user and when I came to setting up his emails we had major issues (it would go in a loop when asking for the password).
I set it up as a POP3 account and this worked. He was able to receive emails however when attempting to send/reply he was receiving the bounce back message; error 550 5.7.1 unable to relay.
They have two domains and both are configured as accepted domains. The users PC is windows XP media center edition.
Any help would be kindly appreciated.