I can send and receive emails through my Verizon account.  I can only receive emails through my client Windows Live Mail.  I am not able to send.  This is the error message I receive:

The message could not be sent because the server rejected the sender's email address.

Subject 'Yes, I Play Ice Hockey'
Server Error: 550
Server Response: 550 5.7.1 Authentication is required to send mail as *** Email address is removed for privacy ***     (THIS IS NOT MY EMAIL ADDRESS)
Server: 'smtp.verizon.net'
Windows Live Mail Error ID: 0x800CCC78
Protocol: SMTP
Port: 465
Secure(SSL): Yes