My original Apple ID is associated with an email address that I no longer have access to.

My original Apple ID is associated with an email address that I no longer have access to. I am attempting to restore an old phone and this old email account is the apple id that is logged in. The email account is one where the domain no longer exists....I can not delete the account as find my phone is turned on and the phone wants me to sign in with the old, non existent id...frustrated..suggestions?