About opt-out keywords for Zendesk Text

Important: You are responsible for using the call and text features in Zendesk Talk in compliance with all applicable laws. Zendesk does not control the content of your telephonic communications, when they are made, or the recipients of the communications. Certain jurisdictions may require end-user consent prior to initiating telephonic outreach. By enabling these features, you agree that you have received the required consent.

Question

My customer sent the word STOP, STOPALL, UNSUBSCRIBE, CANCEL, END, or QUIT in response to one of my Text notifications. Now, I can't send them any messages. How do they change it so they can receive messages again?

Answer 

Zendesk uses Twilio as our provider and by default they handle standard English-language reply messages such as STOP, UNSUBSCRIBE, or CANCEL, in accordance with industry standards. When the customer sends one of the above words, they will be sent the following message:

"You have successfully been unsubscribed. You will not receive any more messages from this number. Reply START to resubscribe."

It is currently not possible to customize the default response triggered by these keywords. However, to receive messages again from your number, the customer will need to reply with START, YES, or UNSTOP.

Additionally HELP and INFO are also key words.

Twilio does not forward HELP/INFO messages to your incoming message webhook. So these one word messages will not create tickets in your Zendesk account.

For more information, see this article from Twilio's Help Center: Twilio support for opt-out keywords (SMS STOP filtering).