You have not entered a valid mail server name when you set up that
account in Windows Mail. You get the correct mail server names from
your mail provider. Who provides your email service?
Or to ask that question another way, what is the part of your email
address after the @ symbol?
Your mail provider will typically have a web page that shows how to
set up an email program. If you need more help, tell us the name of
your email service provider. If you currently don't have an email
address, we can help with that also.