Adding a custom email address for your domain (e.g. hello@yourname.com) is only possible if you own the domain and have access to your DNS settings for that domain.
If you chose a domain from our list when you upgraded, we manage your DNS settings and do all the heavy lifting for you. For domains purchased through us, it is not possible to add email at your domain.
If you mapped a domain you own from a different registrar, like Godaddy, you can add email at your domain and still have your domain point to your about.me page.