Thank you for posting. That error message means the email address does not exist on our server. This can mean a few things. Either the address is misspelled, doesn't exist, or the MX records for the domain are not pointing to our server. Check these things out and if you're still having trouble, let our support team know.
Heather - GoDaddy | Community Moderator 24/7 support available at x.co/247support