One domain for all email accounts?

I am looking for a solution that will allow clients registering WHMC accounts to set up an e-mail address generally available to everyone. And I can not find anything, we currently operate on WHMC + cPanel and the possibility to share the domain to register an e-mail account for all clients is unfortunately not there. (my domain AnotherDomain.com to create e-mail: email@AnotherDomain.com on one client account and email2AnotherDomain.com on another client account) I just want every customer to register an email account in my domain, which he gives him, and then the place counted on his account. Does anyone know if this possibility exists in other panels to manage the hosting? I apologize if my English is illegible.