Section 01
Design for idempotency
Delivery events can arrive more than once or out of order. Your handler should be able to reprocess payloads without duplicating state changes or inbox actions.
Section 02
Separate ingestion from business logic
Accept the event quickly, then hand off to durable processing. That reduces timeout risk and makes debugging easier when load spikes.
Section 03
Observe the full lifecycle
Track inbound receipts, delivery changes, read updates, and failures. The useful output is not only storage of events but operational confidence in how messaging behaves.