You need to follow the email setup instructions from your email
provider or your Internet connection provider. Looks like the
latter is HughesNet? If so, see http://kb.hughesnet.com/al/12/2/1047.htm
If you just try to pick a username yourself, and not set it up
with an email provider (such as your internet provider), you
won't be allowed to use it.
Also, picking names with a space in them makes it very
unlikely they'll work.