portal email not sent for ajax edit vtiger 5.2.*

When the ajax edit for the portal in Contacts, then the system is supposed to send emails to the contacts. but portal emails in vtiger version 5.2.0 as well as 5.2.1 are not sent :(

add this after line 92 in modules/Contacts/DetailViewAjax.php

if($insert == true || $update == true)
  send_mail('Contacts',$modObj->column_fields["email"],
$current_user->user_name,"",$mod_strings["Customer Portal Login Details"],
$contents);