Thanks for posting in The Community. If you are using free email accounts, you may be restricted by the product as to what domains you can use with that email. If you are using hosting-associated email, the domain has to be hosted on that hosting account. If it is, this is how that works: https://www.godaddy.com/help/configuring-mail-clients-with-cpanel-email-8861. Otherwise, purchased email accounts have no such usage restrictions.
I hope that helps,
Thomas D. - GoDaddy | Community Moderator 24/7 support available at x.co/247support