The question is not for my account and for the account of the brother. Not so long ago, his mail was compromised and it is registered in your service other people. Now brother is trying to register on your mail, but it does not work - the attacker managed to confirm the mail brother when registering in PayPal.
Now do the brother if he doesn'T want to create a new email just to register with your service. He is ready to prove that mail, and that it was a misunderstanding.
