I cannot send email.  I get error message 0X800CCC78

Server Error: 530
Server Response: 530 5.7.1 Authentication required
Server: 'smtp.att.yahoo.com'
Windows Live Mail Error ID: 0x800CCC78
Protocol: SMTP
Port: 587
Secure(SSL): No

I have tried some of the suggestions from other messages but none seem to work and there are so many differences.