Comment by oaiey

The bridge between inbox/outbox and queue is not perfect. But it derisks the process a lot. It is much saver to insert a (ideally idempotent) message into the database and then (without transaction) confirm it to the queue than running the whole business process. The likelihood the process will fail is much higher than the inbox / outbox. These patterns also keep your brokers queue empty and allows you to gracefully shutdown your systems.