# SmsDeliveryStatus

A model the API reference uses in a request or a response. The operation pages link every field typed as this model here.

Lifecycle state of a single outbound SMS, as recorded on its `SmsEvents` row. The first three
values are gateway-side outcomes stamped by the platform at send time; the rest arrive later on
Twilio status callbacks.

## Values

| Value | Description |
| --- | --- |
| `Unknown` | No state recorded. Only ever seen on a malformed document. |
| `GatewayBlocked` | The send-time compliance gate refused the message (for example the recipient has opted out). No Twilio API call was made, so no carrier callback will ever follow. Distinct from GatewaySendFailed so a compliance block is auditable separately from a carrier fault. |
| `GatewaySendFailed` | The Twilio API rejected the create-message call. The message never entered the carrier network. |
| `GatewaySent` | Twilio accepted the message. Carrier callbacks (if a status callback URL was set) follow. |
| `Queued` | Carrier callback: the message is queued, accepted, scheduled, or sending. |
| `Sent` | Carrier callback: the message has been handed to the carrier. |
| `Delivered` | Carrier callback: the carrier confirmed delivery to the handset. |
| `Undelivered` | Carrier callback: the carrier could not deliver the message. Usually carries a Twilio error code. |
| `Failed` | Carrier callback: the message failed outright or was cancelled. Usually carries a Twilio error code. |

## See also

- [All documentation](https://devportal.demo.winkpg.io/llms.txt): the machine-readable index of every public page on this site.