Want to delete non working email address Apple keeps using.

I keep getting emails from Apple being sent to a no longer functioning email address that are bounced back to Apple and show nothing in the text body. I’m pretty certain I am also getting the full emails in my working address and the @mac.

I have had zero luck in finding where to delete this non functioning address. In my iCloud acct only the working ones show up and really do not know where else Apple may be keeping my old email address so I can dump it for once and for all.