My outlook express will not send messages and I get the following error:
The message could not be sent because the server rejected the sender's
e-mail address. The sender's e-mail address was '.
Subject '', Account: 'incoming.verizon.net', Server: 'outgoing.verizon.net',
Protocol: SMTP, Server Response: '550 5.7.1 Authentication Required', Port:
25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC78