Here is the Fastest Way to Change your ADMIN EMAIL in General Settings of WordPress without CONFIRMATION (if your wordpress install doesn’t send out emails correctly)
As the heading says, go to the address
yourdomain.com/wp-admin/options.php and find the admin_email section.
Enter your new email address over there, scroll down and save changes.
See the screeshot below.
If you choose this solution then pay attention that no confirmation email is sent.
One email is still sent, though. It goes to the old email address with the notification that “Admin email changed”