public function sendReceipt($recipient, Receipt $receipt, $notificationType = MessageSend::NOTIFICATION_TYPE_REGULAR)
    {
        $structuredMessage = new StructuredMessage($recipient, 
                                                   $receipt, 
                                                   $notificationType, 
                                                   StructuredMessage::ATTACHMENT_TYPE_TEMPLATE,
                                                   StructuredMessage::TEMPLATE_PAYLOAD_TYPE_RECEIPT);
        
        return $this->gate->request(Gate::URL_MESSAGES, $structuredMessage->getDataForCall());
    }