Delivery

The worker processes persistent jobs for individual recipients. It rechecks subscription status before calling the provider. Each delivery has a stable message ID and an idempotency key tied to the campaign and subscriber.

States are queued, accepted, skipped, and failed. Inspect failures with /app/app queue:failed and retry them with /app/app queue:retry.

Retries stop 23 hours after job creation, before Resend's 24-hour idempotency limit. Set QUEUE_CONCURRENCY according to your sending account's limits.