# message_deliveries Webhook Event Reference
This callback will occur when a message a Page has sent has been delivered. You can subscribe to this callback by selecting the `message_deliveries` field when [setting up](https://developers.facebook.com/documentation/business-messaging/messenger-platform/webhooks#setup) your webhook.
## Example {#example}
```
{
"sender":{
"id":"<PSID>"
},
"recipient":{
"id":"<PAGE_ID>"
},
"delivery":{
"mids":[
"mid.1458668856218:ed81099e15d3f4f233"
],
"watermark":1458668856253
}
}
```
## Properties {#properties}
### `sender`
| `sender` Field | Description |
| --- | --- |
| `id` *string* | The Page-scoped ID for the person who sent a message to your business |
### `recipient`
| `recipient` Field | Description |
| --- | --- |
| `id` *string* | The ID for your Facebook Page |
### `delivery` {#delivery}
| Property | Type | Description |
| --- | --- | --- |
| `mids` | Array<String> | Array containing message IDs of messages that were delivered. Field may not be present. |
| `watermark ` | Number | All messages that were sent before this timestamp were delivered |
Both `mids` and `watermark` fields are used to determine which messages were delivered. `watermark` is always present and `mids` is sometimes present. `mids` provides delivery receipts on a per-message basis but may not be present (due to backward compatibility reasons with older Messenger clients). `watermark` is always present and is a timestamp indicating that all messages with a timestamp before `watermark` were delivered.