I set one user up a pop3 account for a domain email account. in the office the user can send/recieve fine. outside the office he gets a 550 requested action not taken. mailbox unavailable which means that the server will not let him relay. the user uses a verizon wireless card which is in the 126.96.36.199 subnet but when he connects the IP address is not consistant. how can I allow him and him only to relay through my server??