{
  "event": "email.delivered",
  "timestamp": "2025-12-27T12:34:56.789Z",
  "email_id": "550e8400-e29b-41d4-a716-446655440000",
  "to": "user@example.com",
  "from": "sender@yourdomain.com",
  "subject": "Welcome",
  "deliveredAt": "2025-12-27T12:34:56.789Z",
  "tag": "campaign-welcome",
  "metadata": {
    "campaign_id": "welcome-2025",
    "customer_segment": "new-users"
  }
}