title: Twilio check if phone number has been blacklisted
body: <p>I am currently integrating into the twilio rest api and need to perform a check on a users phone number to determine if that user has blacklisted themselves or not. I have little experience with this api and scouring through the documentation and google has turned up nothing. </p>
  
  <p>In our application we are going to have a notification center and if the user has blacklisted themselves I do not want to give them the ability to turn on their SMS notifications. Potentially a user could have SMS notifications on but twilio would block any messages. I know there is the ability to get a status code back from twilio when an SMS is queued that shows the user is blacklisted (<a href="https://www.twilio.com/docs/api/rest/message" rel="noreferrer">https://www.twilio.com/docs/api/rest/message</a>). However, I will not be sending messages on the notifications screen and need a direct way (if at all possible) to check twilio to determine if a number is blacklisted. Any help is much appreciated. Let me know if anymore information will be of help.</p>