Three things are enforced by the system itself, not by the AI's judgement. That distinction matters: they hold whether you are in review mode or auto-send, and whether or not anyone is watching.
Every email carries an unsubscribe link. When someone uses it they are suppressed immediately and nothing further is sent to that address — no follow-ups, no new sequence if they come back through a form.
You can suppress an address or a whole domain yourself. Suppression is matched without regard to capitalisation, so a differently-cased address cannot slip past it.
Follow-ups respect quiet hours, so a nudge does not land at 3am. Set them to your customers' timezone rather than your own.
LeadsApp also refuses to email your own domain, so an internal test message cannot start a sequence against your colleagues.
Review your sending settings