protected function sendOfflineWarning(\OxidEsales\Eshop\Core\Exception\StandardException $exception)
    {
        $result = false;
        /** @var  $emailAddress Email address to sent the message to */
        $emailAddress = Registry::get(\OxidEsales\Eshop\Core\ConfigFile::class)->getVar('sAdminEmail');

        if ($emailAddress) {
            /** As we are inside the exception handling process, any further exceptions must be caught */
            $failedShop = isset($_REQUEST['shp']) ? addslashes($_REQUEST['shp']) : 'Base shop';

            $date = date(DATE_RFC822); // RFC 822 (example: Mon, 15 Aug 05 15:52:01 +0000)
            $script = $_SERVER['SCRIPT_NAME'] . '?' . $_SERVER['QUERY_STRING'];
            $referrer = $_SERVER['HTTP_REFERER'];

            //sending a message to admin
            $emailSubject = 'Offline warning!';
            $emailBody = "
                Database connection error in OXID eShop:
                Date: {$date}
                Shop: {$failedShop}

                mysql error: " . $exception->getMessage() . "
                mysql error no: " . $exception->getCode() . "

                Script: {$script}
                Referrer: {$referrer}";

            $mailer = new PHPMailer();
            $mailer->isMail();

            $mailer->setFrom($emailAddress);
            $mailer->addAddress($emailAddress);
            $mailer->Subject = $emailSubject;
            $mailer->Body = $emailBody;
            /** Set the priority of the message
             * For most clients expecting the Priority header:
             * 1 = High, 2 = Medium, 3 = Low
             * */
            $mailer->Priority = 1;
            /** MS Outlook custom header */
            $mailer->addCustomHeader("X-MSMail-Priority: Urgent");
            /** Set the Importance header: */
            $mailer->addCustomHeader("Importance: High");

            $result = $mailer->send();
        }

        return $result;
    }