Ticket #32563: 32563.2.patch

wp-includes/pluggable.php

@@ -1685 +1685 @@
  * @param string $plaintext_pass Optional. The user's plaintext password. Default empty.
  */
 function wp_new_user_notification($user_id, $plaintext_pass = '') {
+
+        if ( ! apply_filters( 'send_new_user_notification', true, $user_id ) )
+                return;
+
         $user = get_userdata( $user_id );
 
         // The blogname option is escaped with esc_html on the way into the database in sanitize_option