Windows Live Mail

Hi, I cannot send mail through the STMP server.  I am getting the following message:

An unknown error was returned from the SMTP server.

Subject 'test'
Server Error: 571
Server Response: 571 impout005 charter.net NDcuMTMzLjE2MC4yMTQ= You must connect from Charter IP space.  E1110
Server: 'smtp.charter.net'
Windows Live Mail Error ID: 0x800CCC61
Protocol: SMTP
Port: 25
Secure(SSL): No

Please advise a solution.   I am receiving email fine.  Thank you.