They used to allow this, but AFAIK they don't anymore. I don't believe you'd be able to sign up a new account with that same email, and if you changed the email

They used to allow this, but AFAIK they don't anymore. I don't believe you'd be able to sign up a new account with that same email, and if you changed the email address on one, you wouldn't be able to change it back. Source: I used to work at Amazon, though never on any systems that would be directly involved in this.