I propose:

random.Domain() - A list of common TLDs will be generated with a valid email
random.DomainAll() - Use the full list from IANA vs just common, look some people still insist on regex email validation
random.Email() - Create a valid email address with a common domain
random.EmailAllDomains() - Create a valid email with a full list of TLDs

We may want to make these RandomDomain with the Random prefix to fit the rest the API, but should eventually move to remove the Random prefix in #333