# Agent Account send queueing

Source: https://developer.nylas.com/docs/changelogs/2026-10-09-agent-account-send-queueing/

## Changed

- **Short bursts above the per-second rate limit are queued instead of rejected.** When an Agent Account sends faster than its organization's [per-second rate limit](/docs/v3/agent-accounts/send-limits/#per-second-send-rate-limit), Nylas holds the extra messages in a short queue and sends them in order. Queued messages usually go out within seconds. A message at the back of a full queue can take up to 90 seconds. This applies to `POST /messages/send` without `send_at`, to sending a draft, and to scheduled messages at their send time.
- **A queued send returns `202 Accepted`.** The response has the same message or draft object as a `200`, without the `headers` array, so `fields=include_headers` and `fields=include_basic_headers` have no effect on a queued send. When the queue is full, the request returns `429` with a `Retry-After` header.
- **Track queued messages with webhooks.** Subscribe to [`message.delivered`](/docs/reference/notifications/agent-accounts/message-delivered/) to confirm that a queued message went out. If Nylas can't send it, [`message.send_failed`](/docs/reference/notifications/messages/message-send_failed/) fires, the message doesn't count against your send quotas, and a queued draft stays in your Drafts folder. See [Send queueing](/docs/v3/agent-accounts/send-limits/#send-queueing).