public function deleteTemplate(Request $request, $id)
    {
        // Find Template
        $mailTemplate = $this
            ->getDoctrine()
            ->getRepository($this->getParameter('pd_mailer.mail_template_class'))
            ->findOneBy(['id' => $id]);

        // Not Found
        if (null === $mailTemplate) {
            $this->addFlash('error', 'sorry_not_existing');

            return $this->redirectToRoute('admin_mail_list');
        }

        // Remove Template
        $em = $this->getDoctrine()->getManager();
        $em->remove($mailTemplate);
        $em->flush();

        // Redirect Back
        return $this->redirect($request->headers->get('referer') ?? $this->generateUrl('admin_mail_list'));
    }