Disable WordPress Auto-Update Email Notifications

Disable Auto Update Plugin and Theme Emails:

//Disable plugin auto-update email notification
add_filter('auto_plugin_update_send_email', '__return_false');
 
//Disable theme auto-update email notification
add_filter('auto_theme_update_send_email', '__return_false');

Disable Auto Update Core Emails:

//Disable automatic "Your Site Has Been Updated..." emails
add_filter( 'auto_core_update_send_email', 'smartwp_disable_core_update_emails', 10, 4 );
function smartwp_disable_core_update_emails( $send, $type, $core_update, $result ) {
  if ( !empty($type) && $type == 'success' ) {
    return false;
  }
  
  return true;
}