We have people signed to multiple lists. It would be perfectly valid for them to unsubscribe from one list and still want to receive messages from other lists. As such, if people unsub they do so from a list and don't go on the superssion list.
Is there any way (an API call for example) to add them to the Supression List programatically? So if they unsub from List A, they can fill in a form/click a button on the Unsub Confirmation page so that they are automatically added to teh Supression List and unsubbed from everything?