src/Checkout/OrderEmailNotifier.php
public function sendReceipt()
    {
        $subject = _t(
            'SilverShop\ShopEmail.ReceiptSubject',
            'Order #{OrderNo} receipt',
            '',
            array('OrderNo' => $this->order->Reference)
        );

        return $this->sendEmail(
            'SilverShop/Model/Order_ReceiptEmail',
            $subject,
            self::config()->bcc_receipt_to_admin
        );
    }
public function sendReceipt()
    {
        $subject = _t(
            'SilverShop\ShopEmail.ReceiptSubject',
            'Order #{OrderNo} receipt',
            '',
            array('OrderNo' => $this->order->Reference)
        );

        return $this->sendEmail(
            'SilverShop/Model/Order_ReceiptEmail',
            $subject,
            self::config()->bcc_receipt_to_admin
        );
    }
Send customer an order receipt email.
Precondition: The order payment has been successful