laravel jobs table keeps queues undeleted after doing the job

I'm using database queue driver of laravel to send email in a production server (laravel forge digitalocean),the email get sended normally but the problem the queues stayed stored in the jobs table and the number increases and keeps attempting to 255
and i did in the listener class

   if($this->attempts() > 10)
        {
            $this->delete();
        }

and nothing get deleted .. what to do to remove them after the email get sended ?

via Chebli Mohamed