Cannot send with smtpauth.centurytel.net: error 0x800CCC79

... This is the message I get.

The message could not be sent. The setting for your outgoing email [SMTP] server might need to be configured. To find the server settings for '*** Email address is removed for privacy ***', please contact your email service provider.

Subject 'test'
Server Error: 550
Server Response: 550 5.7.1 <*** Email address is removed for privacy ***>... Relaying denied - SMTP authentication is required. Ensure all outbound connections are configured to authenticate.  Please call 800-788-3600 if assistance is required
Server: 'smtpauth.centurytel.net'
Windows Live Mail Error ID: 0x800CCC79
Protocol: SMTP
Port: 587
Secure(SSL): No

Split from an unrelated thread