# View SMS Delivery Events

Engage Studio writes SMS delivery activity to event tables for your workspace. Use these tables to verify whether messages were accepted and delivered, investigate send failures, find quiet-hours blocks, and keep opt-out audiences current.

## Event Tables

SMS events are written to the `delivery_sms_<workspace_id>` database for your workspace.

| Table | What it contains |
|  --- | --- |
| `events` | Post-send status for messages, including `sent`, `delivered`, and `failed`, plus `quiet_hours_blocked` records |
| `error_events` | Failures before a message is accepted by Twilio or after the delivery request fails after retries are exhausted |
| `subscription_events` | Opt-out and opt-in events received from SMS keywords such as STOP and START |


Click events from shortened links are stored separately in `delivery_links_<workspace_id>.link_click_events`. See [Track Clicks in SMS Campaigns](/ja/products/marketing-cloud/engage-studio/channels/sms/track-clicks-in-sms-campaigns).

## Interpret Delivery Status

- `sent` means the delivery pipeline accepted the message for sending.
- `delivered` means the delivery provider reported successful delivery.
- `failed` means the provider reported that delivery did not succeed.
- `quiet_hours_blocked` means Engage Studio prevented the message from being sent because the campaign was outside its configured delivery window.


A `quiet_hours_blocked` message is not automatically retried. See [Configure SMS Delivery Windows](/ja/products/marketing-cloud/engage-studio/channels/sms/configure-sms-delivery-windows).

## Keep the Audience Current

Use `subscription_events` to identify recipients who opted out. Opt-out events do not automatically remove profiles from the Parent Segment. Update your audience or activation before the next campaign so that opted-out recipients are excluded.

See [Manage SMS Consent and Opt-Outs](/ja/products/marketing-cloud/engage-studio/channels/sms/manage-sms-consent-and-opt-outs) for keyword behavior and re-opt-in requirements.

## Related Pages

- [Create an SMS Campaign](/ja/products/marketing-cloud/engage-studio/channels/sms/create-sms-campaign)
- [Troubleshoot SMS Delivery](/ja/products/marketing-cloud/engage-studio/channels/sms/troubleshoot-sms-delivery)
- [Track Clicks in SMS Campaigns](/ja/products/marketing-cloud/engage-studio/channels/sms/track-clicks-in-sms-campaigns)