Outlook express email?

I get this error when I want to send out mail on outlook express. I need to correct this because I have to return emails and when I try I get this message. The service is currently unavailable. Try again later. Account: 'Hotmail', Server: 'http://services.msn.com/svcs/hotmail/htt... Protocol: HTTPMail, Server Response: 'Service Unavailable', Port: 0, Secure(SSL): No, Error Number: 0x800CCCF0





How do I correct this so I can send out mail?
Outlook express email?
Make sure that you have the "My server requires authentication" box clicked on the Servers tab from Email accounts-Properties. Some servers require this. Yahoo does.