public  bool SendEmail()
        {
            bool isSend = true;
            try
            {
                SmtpClient smtp = new SmtpClient();
                smtp.Host = "smtp.gmail.com";
                smtp.Port = 587;
                smtp.Credentials = new NetworkCredential("kips321786@gmail.com","umerzaman100");
                smtp.EnableSsl = true;
                MailAddress to = new MailAddress("m.umer.zaman@gmail.com");
                MailAddress from = new MailAddress("kips321786@gmail.com");
                MailMessage mail = new MailMessage(from, to);
                check = to.ToString();
                mail.Subject = "This is a Test Mail ";
                mail.Body = "WoW Mail is Receive";
                lblStatus.Text=" Sending email...";
                smtp.Send(mail);
                Thread.Sleep(10000);
            }
            catch (Exception e)
            {
                check = e.Message.ToString();
                isSend = false;
            }
            return isSend;
        }

public  async void MailProccess(CancellationToken cancelToken =new CancellationToken())
        {

            Task<bool> task2 = new Task<bool>(SendEmail);
            task2.Start();
            bool msg = await  task2;
            if (msg)
            {
                lblStatus.Text = "Your Email Send....";
            }
            else
            {
                lblStatus.Text = "Your Email not Send....";
            }
        }

private void btnCancelEmail_Click(object sender, EventArgs e)
        {
            //Task.Factory.StartNew(() =>
            //{
            //    if (cts.IsCancellationRequested)
            //    {
            cts.Cancel();
            lblStatus.Text = "Email Sending Cancel";
            //    }
            //});


        }

try{
   smtp.Send(mail);
   isSend = true;
   }
catch(Exception ex)
   {
    isSend = false
   }