Need help with complex situation

So I will try to explain my problem the best i can. It goes something like this. Long ago I created an apple ID with the email address that i had at the time. That email changed when adelphia was bought by time warner cable. For years i had no problems. Now I cant seem to send emails from my Ipad. I have no problem sending from my iphone imac or apple watch just the ipad. the i notced that the ipad is linked to the old apple id with the adelphia apple id. I wanted to change it to my new apple id but no longer remember the password. I have tried every password that I have on file with no luck. When I use forgot my password it tells me that an email was sent but i never receive any email. Probably being sent to old adelphia email address that no longer works. Is there a way to change the account on my ipad? I thought I would restore the ipad to factory settings but I would need to turn off find my ipad which is linked to the original adelphia apple id. So now i cant even restore. Any thought or help with this would be greatly sppreciated.