can not send email
by ted-june - 1/29/13 7:43 AM
Windows Live Mail Error ID: 0x800CCC78
The message could not be sent because the server rejected the sender's email address. The sender's email address was 'firstname.lastname@example.org'
Server Error: 503
Server Response: 503 you must authenticate first (#5.5.1)
Any help would be greatly appreciated