I would think your Email server address would have to be the Godaddy server address. I think you only leave that blank to use the local host server. But I could be wrong.
CDONTS doesn't support authentication. In order to use an external mail server you will more than likely need to use a username (email address) and password along with the mail server address. CDOSYS does support this and you have to edit inc_mail.asp. Search this forum for CDOSYS to find out how.