public function sendMail(Request $request)
    {
        if (null === $mail = $request->request->get('email')) {
            $this->app->abort(400, 'Bad request missing email parameter');
        };

        if (!\Swift_Validate::email($mail)) {
            $this->app->abort(400, 'Bad request missing email parameter');
        };

        try {
            $receiver = new Receiver(null, $mail);
        } catch (InvalidArgumentException $e) {
            return $this->app->redirectPath('admin_dashboard', ['email' => 'not-sent']);
        }

        $mail = MailTest::create($this->app, $receiver);

        $this->deliver($mail);

        /** @var \Swift_SpoolTransport $spoolTransport */
        $spoolTransport = $this->app['swiftmailer.spooltransport'];
        /** @var \Swift_Transport $transport */
        $transport = $this->app['swiftmailer.transport'];
        $spoolTransport->getSpool()->flushQueue($transport);

        return $this->app->redirectPath('admin_dashboard', ['email' => 'sent']);
    }