If he ultimately got through with a free e-mail address, that was likely a mistake on behalf of the person who accepted him and should not be allowed.
However, if he used a normal internet service provider, work, school, or other paid e-mail address, then it is fine.
If you want us to help you further we do need more details about the situation, as well as a description of what problem you are currently having. Are you still having trouble creating your own account? What information are you entering?