My Windows Live Mail has been working fine up until yesterday. Now I am getting this message when I try to send mail out:

The message could not be sent because the server rejected the sender's email address. The sender's email address was '*** Email address is removed for privacy ***'.

Server Error: 530
Server Response: 530 Authentication is required before sending [R0107005]
Server: 'SMTP-server.twcny.rr.com'
Windows Live Mail Error ID: 0x800CCC78
Protocol: SMTP
Port: 587
Secure(SSL): No

My settings have not changed since I started using Windows Live Mail 2 years ago. I checked for updates, and can not figure this out. Can anyone help?

Thank you!!