Allow Duplicate Email Address for Different Users
Unfortunately, this just isn’t possible. There are three occasions where WordPress performs this check: When you click ‘save’ on the edit user screen( https://github.com/WordPress/WordPress/blob/master/wp-admin/includes/user.php#L157 ) When a user is registered ( https://github.com/WordPress/WordPress/blob/master/wp-includes/user.php#L2023 ) When a user is created/inserted into the dtabase ( https://github.com/WordPress/WordPress/blob/master/wp-includes/user.php#L1610 ) Both (1) and (2) have hooks after them which allow you … Read more