cannot send email in windows mail see error message below

The host 'POP@xxxxxxxxxx' could not be found. Please verify that you have
entered the server name correctly.
Subject 'Tax surplus list', Account: 'IMAP@xxxxxxxxxx', Server:
'POP@xxxxxxxxxx', Protocol: SMTP, Port: 25, Secure(SSL): No, Socket Error:
11003, Error Number: 0x800CCC0D

Please help I am a newbie I am using
windows vista