If you are in such a situation that you are away from home, say in college, there are two ways around this:
-Use Cox's webmail
-Specify an alternate SMTP server, that you have access to such as your school's mail server, in your e-mail client.
You will probably prefer to use an e-mail client. The incoming server will not change, but you will need to consult your network administrator on getting details for changing your SMTP server.