title: c# MailSender and sleep
body: <p>I am writing a program that sends email through class SmtpClient. I use this code:</p>
  
  <pre><code>        try
          {
              MailMessage mail = new MailMessage();
              SmtpClient SmtpServer = new SmtpClient("mailSMTP.it");
  
              mail.From = new MailAddress("address.it");
  
              mail.Subject = "oggetto";
  
              mail.IsBodyHtml = true;
              string htmlBody = "someHTML";
  
              mail.Body = htmlBody;
  
              SmtpServer.Port = 25;
  
              SmtpServer.EnableSsl = false;
  
              foreach (string indirizzo in indirizzi)
              {
                  mail.To.Clear();
                  mail.To.Add(indirizzo);
                  SmtpServer.Send(mail);
                  System.Threading.Thread.Sleep(3000);
              }
  
              MessageBox.Show("e-mail spedite!");
  
          }
          catch (Exception ex)
          {
              MessageBox.Show(ex.ToString());
          }
  </code></pre>
  
  <p>but it only works if I cut the "Sleep" line. Why? I thought it was a good idea to make a rest during that process. </p>