Event types

Email events

email.sent

The email was accepted by the receiving MTA. Not yet delivered to the recipient’s inbox.

{
  "type": "email.sent",
  "created_at": "2026-04-22T22:30:02Z",
  "data": {
    "email_id": "a1b2...",
    "to": "[email protected]",
    "from": "[email protected]",
    "subject": "Your receipt",
    "smtp_ip": "142.54.161.92"
  }
}

email.delivered

The email landed in the recipient’s mailbox (or was placed in their spam folder — both count as delivered from an SMTP standpoint).

{
  "type": "email.delivered",
  "data": {
    "email_id": "a1b2...",
    "delivered_at": "2026-04-22T22:30:04Z"
  }
}

email.bounced

Delivery failed. Hard bounces add the recipient to the suppression list.

{
  "type": "email.bounced",
  "data": {
    "email_id": "a1b2...",
    "bounce_type": "hard",
    "bounce_detail": "550 5.1.1 The email account does not exist"
  }
}

bounce_type is one of hard, soft, block.

email.complained

The recipient marked the email as spam (received via FBL). Suppression is permanent.

{
  "type": "email.complained",
  "data": {
    "email_id": "a1b2...",
    "complained_at": "2026-04-22T23:15:00Z"
  }
}

email.opened

The tracking pixel was loaded.

{
  "type": "email.opened",
  "data": {
    "email_id": "a1b2...",
    "opened_at": "2026-04-22T22:35:00Z",
    "user_agent": "Mozilla/5.0 ..."
  }
}

Note: Apple Mail Privacy Protection auto-loads images, inflating opens. Treat clicks as the real engagement signal.

email.clicked

A link in the email was clicked.

{
  "type": "email.clicked",
  "data": {
    "email_id": "a1b2...",
    "clicked_at": "2026-04-22T22:36:00Z",
    "url": "https://acme.com/product/123",
    "user_agent": "Mozilla/5.0 ..."
  }
}

email.failed

Permanent failure (not a bounce — usually a configuration issue or DNS-level rejection).

{
  "type": "email.failed",
  "data": {
    "email_id": "a1b2...",
    "error": "DNS lookup failed for example.com"
  }
}

Campaign events

campaign.sent

Fires when a campaign finishes sending all queued emails (regardless of delivery status).

{
  "type": "campaign.sent",
  "data": {
    "campaign_id": "camp_a1b2...",
    "total_recipients": 19872,
    "sent_count": 19850,
    "failed_count": 22
  }
}

campaign.delivered

Fires once per campaign when delivery confirmations have been received for all sent emails.

campaign.auto_paused

Fires when a campaign is auto-paused due to a circuit-breaker tripping.

{
  "type": "campaign.auto_paused",
  "data": {
    "campaign_id": "camp_a1b2...",
    "reason": "complaint_rate_threshold_exceeded",
    "metric_value": 0.0012,
    "threshold": 0.001
  }
}

Subscription

Subscribe to events when you create the webhook:

{
  "url": "https://yourapp.com/webhooks",
  "events": ["email.delivered", "email.bounced", "email.complained", "campaign.auto_paused"]
}

Subscribe to all events with the wildcard:

{ "events": ["*"] }