title: Should I use thread.sleep or timer in my code?
body: <p>I have the following code which send out SMS to the subscribers. However, some SMS were rejected from the SMSGateway because I'm sending too many SMS at one time. So I'm thinking to make a delay in between. </p>
  
  <p>Sending out the SMS like this -</p>
  
  <pre><code>            foreach (DataRow row in dt.Rows)
              {
                  //Gets Subscriber number
                  smsSender.destinationNum = Convert.ToInt64(row["callerID"]);
                  foreach (DataRow articleRow in dtArticle.Rows)
                  {
                      //Gets SMS content
                      smsSender.smsMessage = articleRow["news"].ToString();
                      //Then send out the SMS
                      smsSendder.sendSMS();
                  }
              }
  </code></pre>
  
  <p>Please advice because I have no experience with the threads and timers</p>