http://unbejuoettmdo3n63viehycdvp5b5cym4wbn5pqn27fbaudfj5yk7tqd.onion/howto
Create a new e-mail address somewhere, just for this purpose, use that address exclusively for darknet activity (for example, regularly buying products from us), and forget/delete that address completely, if you think you're done with the Darknet.