Announcing Webhooks v2

We’re launching Webhooks v2, a complete overhaul of how Emailit delivers real-time event notifications to your applications. With 36 event types across 9 resource categories, cryptographic signature verification, and a robust retry policy, Webhooks v2 gives you everything you need to build reliable, event-driven integrations.

What’s new

36 event types across 9 resources

Webhooks v2 covers every resource in Emailit. You can subscribe to exactly the events you care about or use all_events to receive everything.

Email events track the full delivery lifecycle:

Event	Description
email.accepted	Accepted for delivery
email.scheduled	Scheduled for future delivery
email.delivered	Delivered to the recipient’s mail server
email.bounced	Permanently failed (hard bounce)
email.attempted	Temporary delivery failure
email.failed	Failed due to a specific error
email.rejected	Accepted then rejected
email.suppressed	Recipient is on the suppression list
email.received	Incoming email was accepted
email.complained	Spam complaint registered
email.clicked	A link in the email was clicked
email.loaded	Email content was loaded (opened)

CRUD events for domains, audiences, subscribers, contacts, templates, suppressions, email verifications, and email verification lists, each with .created, .updated, and .deleted events.

Consistent event structure

Every webhook payload follows the same shape, making it straightforward to build a single handler for all events:

{
  "event_id": "evt_2bH7kNwP5mQaV1sXgIdKe6pZr",
  "type": "email.delivered",
  "data": {
    "object": {
      "id": "em_4yM2nTvR8oPcX3uZiKeLg7sB",
      "object": "email",
      ...
    }
  }
}

The event_id uniquely identifies each event, type tells you what happened, and data.object contains the full resource at the time of the event.

HMAC-SHA256 signature verification

Every webhook request is signed with your webhook secret using HMAC-SHA256. The signature is computed over {timestamp}.{rawBody}, so you can verify both authenticity and freshness in one step.

Each request includes two headers:

• X-Emailit-Signature — the HMAC-SHA256 hex digest
• X-Emailit-Timestamp — the Unix timestamp used in the signature

We strongly recommend using timing-safe comparison (e.g. crypto.timingSafeEqual in Node.js) to prevent timing attacks, and rejecting requests with timestamps older than a few minutes to guard against replay attacks.

Full verification examples in Node.js, Python, PHP, Ruby, and Go are available in the Request Signature documentation.

Automatic retries with exponential backoff

If your endpoint doesn’t respond with a 2xx within 30 seconds, Emailit retries automatically:

Attempt	Delay
0	5 seconds
1	5 minutes
2	30 minutes
3	2 hours
4	5 hours
5	10 hours
6	24 hours

That’s 7 total attempts over roughly 41 hours. After the final attempt, the webhook is automatically disabled. You can re-enable it from the dashboard at any time.

Request format

All webhook requests are POST with a JSON body. Each request includes these headers:

Header	Description
Content-Type	application/json
User-Agent	Emailit-Webhook/1.0
X-Emailit-Signature	HMAC-SHA256 signature
X-Emailit-Timestamp	Unix timestamp used in signature

Best practices

• Respond quickly — Return a 2xx immediately and process the payload asynchronously in a background job.
• Handle duplicates — The same event may be delivered more than once during retries. Use event_id to deduplicate.
• Verify signatures — Always validate the X-Emailit-Signature header to confirm the request came from Emailit.
• Guard against replay attacks — Check the X-Emailit-Timestamp and reject requests older than a few minutes.

Full documentation

We’ve published complete documentation for Webhooks v2 with detailed payload examples and field descriptions for all 36 events:

• Introduction — Overview and how webhooks work
• Event Types — Complete list of all 36 event types
• Webhook Requests — Request format, headers, and retry policy
• Request Signature — Signature verification with code examples in 5 languages

Get started

Head over to the Webhooks documentation to get started, or jump straight to the API Reference to create your first webhook endpoint.