I cannot find which “primary” email address is associated with Apple ID and therefore cannot reset my password
Recently, my father bought a new iPhone 6, but messed up setting his iCloud. I cannot find which “primary” email address is associated with his Apple ID and therefore cannot reset his password. He set an ID ending at ******@icloud.com. My question is how can I reset the password for the ID if the “Reset password” email from Apple is send to @icloud.com to which I have no access, and how can I get into iCloud Mail.
iPhone 6 Plus, iOS 9.0.2