Why Can't I Send Mail from My Email Software?
First, make sure you listed the correct entry for "Outgoing Mail (SMTP)" when you set up POP. This entry should be in the format: "smtp.myisp.com", where "myisp.com" is your Internet Service Provider's Web Address. For example, customers who get Internet access from Earthlink® would use, "smtp.earthlink.net".
Some Internet Service Providers may block the use of their Outgoing Mail (SMTP) server if you try to use an e-mail address that was not been assigned by your ISP. If you are still having trouble sending outgoing mail, contact your ISP to verify if you can use their SMTP server or contact Customer Service at http://goto.networksolutions.com/contactus for alternatives.