Yes, with over 21,000 members Audiokarma has chosen to ban all free email accounts in an attempt curb the massive attacks of spammers. No Yahoo, Gmail, Hotmail, and over 2000 over accounts that are being used by spammers are allowed. It even mentions no free email accounts when you signup and are asked for your email. So, it wasn't a personal denial for you but for anyone trying to use a free email account or ISP accounts that have been used by spammers.