protected function registerRoutes(Router $router)
    {
        $debug = $this->app->make(MailDebugManager::class);

        $router->get('mail-debug/{file}', function ($file) use ($debug) {
            if (file_exists($path = $debug->storage().'/'.$file)) {
                include $path;
                return;
            }

            return abort(404);
        })->name('mail-debug');
    }