The $3500 ICANN registration fee and the accompanying $4000 yearly accreditation fee hardly make running your own personal registrar worth it, and that doesn't even cover the necessary legal fees and paperwork you need to fill out to become a proper registrar.

The entire process also seems rather lengthy to me if all you want is set up secure email: https://www.icann.org/resources/pages/accreditation-2012-02-...