private void sendmail_dodano_zlecenie()
        {
            SmtpClient client = new SmtpClient();
            client.Port = 587;
            client.Host = "smtp.gmail.com";
            client.EnableSsl = true;
            client.Timeout = 10000;
            client.DeliveryMethod = SmtpDeliveryMethod.Network;
            client.UseDefaultCredentials = false;
            client.Credentials = new System.Net.NetworkCredential("twojmail@mail.com", "haslo");

            MailMessage mm = new MailMessage("twojmail@gmail.com", "kogosmail@hotmail.com");
            mm.Subject = "Tytuł";
          //  string wiadomosc = String.Format("Uwaga! \n Dodano nowe zleceni({0}) do bazy!",label2.Text);
            mm.Body = wiadomosc;
            mm.BodyEncoding = UTF8Encoding.UTF8;
            mm.DeliveryNotificationOptions = DeliveryNotificationOptions.OnFailure;
            client.Send(mm);
        }