If your customers wish to stop receiving messages from you, all they need to do is respond with: STOP, STOPALL, UNSUBSCRIBE, CANCEL, END, or QUIT.
Default reply: You have successfully been unsubscribed. You will not receive any more messages from this number. Reply START to resubscribe.
Any of these STOP keyword replies will prevent a customer from receiving new messages from the LaunchSMS phone number they’re responding to. When LaunchSMS receives one of these replies, we will create a “blacklist” entry on our side, and then pass the message on. Once we have a blacklist entry for a particular recipient phone number, any future attempts to message them will be met with a 400 response from our API, along with Error Code 21610 – Message cannot be sent to the ‘To’ number because the customer has replied with STOP. Recipients can disable this message stop, and resume receiving messages with the START, YES, or UNSTOP commands as outlined below.
Only single-word messages will trigger the block. So, for example, replying STOP will stop the customer from receiving messages from that particular Twilio number, but replying “STOP PLEASE” or “PLEASE CANCEL” will not. Further, the block works and is logged even if your number currently has no messaging request URL.
Please note that these STOP keyword replies only apply to the most recent number that messaged the recipient. If you are using more than one Toll-Free number or Long Code for sending messages, you must take additional action separate from LaunchSMS to prevent these customers from receiving messages from your other numbers. We recommend “blacklisting” numbers on your side when one of these message responses is received at your webhook.
Because your customer has already done business with you, and in many cases agreed to leave feedback, there is no legal requirement to include an ‘opt out’ in each message. As long as it isn’t a marketing promotion you do not have to display the opt-out information.