Treat recipient suppression as a durable compliance decision, not as a flag buried inside an SMS provider. For every scheduled fintech alert, resolve the recipient against an internal, append-only suppression ledger immediately before dispatch; record the policy version and evidence used; then accept delivery events asynchronously and idempotently. This preserves an explanation for why a message was sent or withheld even after a provider, phone number, or retention policy changes. Short answ...