# New Delivery Failure (Instant) — Mailgun

> Emit new event when an email can't be delivered to the recipient email server.

- Key: `mailgun-new-delivery-failure`
- Type: Trigger (Instant)
- Version: 0.0.2
- App: Mailgun (`mailgun`) — https://pipedream.com/apps/mailgun.md
- This page (HTML): https://pipedream.com/apps/mailgun/triggers/new-delivery-failure
- Source: https://github.com/PipedreamHQ/pipedream/blob/master/components/mailgun/sources/new-delivery-failure/new-delivery-failure.mjs

## Props

| Prop | Type | Required | Description |
|---|---|---|---|
| `domain` | `string` | Yes | Options are loaded from the connected account. |
| `webhookSigningKey` | `string` | Yes | Your Mailgun webhook signing key, found in your Mailgun dashboard, located under Settings on the left-hand nav and then in API Keys look for webhook signing key. Required to compute the authentication signature of events. |

## Returns

Events emitted by Mailgun.

## Run it

**TypeScript**

```ts
import { PipedreamClient } from "@pipedream/sdk"

const pd = new PipedreamClient({
  projectId: process.env.PIPEDREAM_PROJECT_ID!,
  clientId: process.env.PIPEDREAM_CLIENT_ID!,
  clientSecret: process.env.PIPEDREAM_CLIENT_SECRET!,
  projectEnvironment: "production",
})

const deployed = await pd.triggers.deploy({
  id: "mailgun-new-delivery-failure",
  externalUserId: "{external_user_id}", // any stable ID for this user in your system
  configuredProps: {
    mailgun: { authProvisionId: "apn_xxxxxxx" },
    domain: "Domain Name",
    webhookSigningKey: "Mailgun webhook signing key",
  },
  webhookUrl: "https://example.com/webhooks/mailgun",
})

console.log(deployed.id)
```

**cURL**

```bash
curl -X POST https://api.pipedream.com/v1/connect/{project_id}/triggers/deploy \
  -H "Content-Type: application/json" \
  -H "X-PD-Environment: production" \
  -H "Authorization: Bearer {access_token}" \
  -d '{
    "external_user_id": "{external_user_id}",
    "id": "mailgun-new-delivery-failure",
    "webhook_url": "https://example.com/webhooks/mailgun",
    "configured_props": {
      "mailgun": { "authProvisionId": "apn_xxxxxxx" },
      "domain": "Domain Name",
      "webhookSigningKey": "Mailgun webhook signing key"
    }
  }'
```

**MCP**

MCP servers expose Mailgun actions as on-demand tools.

New Delivery Failure (Instant) is an event source, so your application deploys it with the Connect SDK or API and then either receives each event at a webhook URL or retrieves events on demand with the trigger events API.

## Event delivery

Every event is sent to the HTTP endpoint you choose when you deploy the source. Or: no webhook required — your app or agent can fetch recent events from the [trigger events API](https://pipedream.com/docs/connect/api-reference/list-trigger-events.md) instead.

---

- App: https://pipedream.com/apps/mailgun.md · All apps: https://pipedream.com/apps