Hi,
Looking at the source code of this BrainForge plugin, I see a source of 403:
if ($hostError > 0) {
$mailer->setSubject(JText::sprintf('NOTIFICATION_REFUSED_FOR_THE_ORDER','Worldpay Business Gateway').' '.JText::sprintf('IP_NOT_VALID',hikashop::encode($dbOrder)));
$body = str_replace('<br/>',"\r\n",JText::sprintf('NOTIFICATION_REFUSED_FROM_IP','Worldpay Business Gateway',$ip,'See Hostname / IPs defined in configuration'))."\r\n\r\n".JText::sprintf('CHECK_DOCUMENTATION',HIKASHOP_HELPURL.'payment-rbsworldpay-error#ip').$order_text;
$mailer->setBody($body);
$mailer->Send();
JError::raiseError( 403, JText::_( 'Access Forbidden' ));
return false;
}
Did you receive an email from your website with that kind of message (IP refused) ?
There are two options "Notification hostname" and "IPs" that you can empty if you want to not check the worldpay ips.
If these values are wrong, it will explain why the notification is refused.
Regards,