> ## Documentation Index
> Fetch the complete documentation index at: https://docs.reallyquickemails.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Event tracking

> How events, open and click tracking, and suppressions work.

For each email you send, RQE fires a webhook with events as they happen. Some come from the sending provider (delivery, bounce); others are detected by RQE directly (open, click).

## Available events

| Webhook event         | When it fires                                    | Reliability |
| --------------------- | ------------------------------------------------ | ----------- |
| `email.send`          | RQE accepted the send and dispatched it          | 100%        |
| `email.delivery`      | The recipient's server accepted the email        | \~99%       |
| `email.bounce`        | Email bounced (hard or soft)                     | 100%        |
| `email.complaint`     | Recipient marked as spam                         | 100%        |
| `email.deliverydelay` | Delivery temporarily delayed                     | 100%        |
| `email.open`          | Recipient opened the email                       | \~70%       |
| `email.click`         | Recipient clicked a link                         | \~99%       |
| `email.inbound`       | Recipient replied to your email (API sends only) | 100%        |

There's also `email.reject` (send rejected before going out). The details of each event and its fields are in the [Webhooks reference](/en/api-reference/webhooks#events).

## Bounces — soft vs hard

| Type            | Description                           | RQE's action                                                                          |
| --------------- | ------------------------------------- | ------------------------------------------------------------------------------------- |
| **Hard bounce** | Address doesn't exist (`550 5.1.1`)   | Adds the recipient to the suppression list — the next sends are skipped automatically |
| **Soft bounce** | Mailbox full, server temporarily down | Marks the event, doesn't add to suppression. You can send again                       |

Complaints (`email.complaint`) also add the recipient to the suppression list automatically.

<Warning>
  Above **2%** bounces, your deliverability degrades. Above **5%**, the provider may suspend your sending. Clean your list: an old email is a bounce waiting to happen.
</Warning>

## Open tracking

RQE injects a transparent 1x1 pixel into the HTML. When the recipient's client loads images, it fires `email.open`.

### Why reliability is approximate

* **Outlook desktop** blocks external images by default → no open detected
* **Apple Mail iOS 15+** with MPP (Mail Privacy Protection) loads the pixel automatically on receipt → reports an open before the user actually opens
* **Plain-text clients** → don't load images

<Info>
  **Treat opens as approximate**

  Opens are a trend signal (does this send get opened by more people than that one?), not exact individual behavior. For real conversion, look at clicks.
</Info>

## Click tracking

Before sending, RQE rewrites the `<a href>` tags in the HTML so they pass through a tracking endpoint that does a 302 redirect to the original destination. The redirect is instant, the user doesn't notice anything. It only fails if they copy/paste the href manually (extremely rare).

## Webhook payload

Your `webhook_url` receives a POST with an HMAC-SHA256 signature in the `X-RQE-Signature` header, signed with your project's API key. Example body for `email.delivery`:

```json theme={null}
{
  "event": "email.delivery",
  "is_test": false,
  "timestamp": "2026-04-29T15:30:42.123Z",
  "project_id": "...",
  "data": {
    "activity_id": "...",
    "message_id": "...",
    "recipient": "user@example.com",
    "event_type": "delivery",
    "event_timestamp": "2026-04-29T15:30:42.000Z"
  }
}
```

For the full shape by event type, see [Webhooks → Outbound payload](/en/api-reference/webhooks#outbound-payload).

### HMAC verification in Node

```javascript theme={null}
const crypto = require('crypto');
const expected = 'sha256=' + crypto
  .createHmac('sha256', apiKey)
  .update(rawBody)
  .digest('hex');
if (req.headers['x-rqe-signature'] !== expected) {
  return res.status(401).send('Invalid signature');
}
```

## Next steps

* [Webhooks](/en/api-reference/webhooks) — full reference with all formats.
* [Test mode](/en/concepts/test-mode) — separate dev vs prod tracking.