where do you go to view a email to help unlock your apple ID after many failed attempts of putting the password in?

asking this for my dad since I forgot his password and have failed to put it in many times and trying to unlock it, I forgot most of the security questions that are for so far lack of anything he can pick or have an accurate answer to, but moving on this is over the viewing of the email that's suppose to help unlock it, any idea where? or if I can make it email my phone or email account, tried the apple mail and Gmail but so far... none of them work less I'm looking in the wrong place, just asking for a hand here so.. help? anyone?