Original email (OGE)

The email address the account was created with — whoever controls it controls the account.

Game publishers treat the first email on an account as proof of ownership: recovery requests, ban appeals and password resets all go there. An account sold with its original email can be made safe by changing that email; one sold without it can be recovered by the original owner at any time. On listings the field "email change: yes" means the original email is included.