Email problem

hope someone can help me ??,I get this message after one message. Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Account: ‘david.colligan@ntlworld.com’, Server: ‘pop.ntlworld.com’, Protocol: POP3, Port: 110, Secure(SSL): No, Error Number: 0x800CCC0F