You can teach the system to trigger certain actions based on the content of the inbound messages. Using this alongside groups in contacts you can manage your opt-outs automatically!
If you configure a flow as shown below, those users who reply ‘Stop’ will be automatically removed from the group specified. When sending out a campaign, make sure your contacts are in a group.
This will remove the contacts from the group, but they will remain in your address book.
You can also create multiple flows if you need to keep track of all opt-outs for your own reference. You can set up something like this:
If you're submitting via an API connection, and want to manage opt-outs, we recommend doing so on your side of the connection to avoid confusion.