When sending messages, you are legally required to opt someone out of a Program's texting list each time they ask to be removed by replying "please stop", "don't contact me", "unsubscribe," "stopall," "cancel," "end," "quit," or anything similar.
To Opt-Out a contact, you simply use the Opt-Out reply in the program script. Using any scripted reply set to Script Type = Opt-Out will trigger the system to automatically opt that contact out of that program's list.
Opt-outs will occur automatically when someone uses the word "STOP." When this happens the conversation will be removed and you will no longer be able to view it.
There may be additional guidelines your organization follows related to opt-outs. Ask your organization about any additional opt-out guidelines they may have.