To send email you will need to configure your email program with "mail.yourdomainname" as the outgoing email server (also known as SMTP server). Additionally, to send email, you will first need to check email by using "mail.addr.com" as your incoming mail server (also known as POP3).
The solution in this case, would be to send email through mail.earthlink.net
or vipmail.earthlink.net. Should you have any
questions about EarthLink and MindSpring policies, please
don't hesitate to get in touch with their technical support
department.