title: STOP receiving SMSes when using Twilio with C#.net
body: <p>I am sending SMS via <a href="https://www.twilio.com/docs/csharp/install" rel="nofollow">twilio C#</a> to selected phone numbers.
  I see in FAQs in twilio that it is possible to filter out the numbers who do not wish to receive SMSes. I see this kind of information in the link:
  <a href="https://www.twilio.com/help/faq/sms/does-twilio-support-stop-block-and-cancel-aka-sms-filtering" rel="nofollow">https://www.twilio.com/help/faq/sms/does-twilio-support-stop-block-and-cancel-aka-sms-filtering</a></p>
  
  <p>My questions are:</p>
  
  <p>1) When user replies STOP, how does twilio handles it?</p>
  
  <p>2) How will my application know that someone has replied "STOP" and opted out from receiving messages?  (Actually I want to update database when someone replies "STOP" to twilio and unsubscribe) </p>