going in circles - new email address and email provided by gmail

I have a domain that has email accounts. It was established a long time ago. I want to add a new email address for that domain. The MX records point at google. I try to create a new google account but can not because it wants to verify the new address, which gmail does not recognize. The automatic account setup fails when google wants to verify the address. So, I can't add a google account email because it doesn't exist. Suggestions please,