SMS Marketing requires users to opt-in to receive messages and in many cases requires them to initially request the messages from their mobile number. If you're having issues delivering messages to people, follow these steps to troubleshoot:
- Make sure they are set to Opt-In for SMS. You can check this on their CRM profile
- If they're still not receiving messages, this may be due to them opting out previously. In this case, if they simply reply Start to your number, this will then re-activate their account.