In instances where the recipients want to opt-out but have misspelled the "opt-out" response or have a replied with an opt out request other than STOP, UNSUBSCRIBE, UNSUB or END, you can process them MANUALLY by clicking on OPT-OUT from the Actions column beside the reply. It is a good idea to always review the RESPONSES tab and check for these. If they are not removed and subsequent messages are sent, this can generate a complaint.