email.opened

​

Payload

{
  "id": "whd_3Fn8kR2vB",
  "event": "email.opened",
  "createdAt": "2026-09-11T10:12:47.390Z",
  "data": {
    "messageId": "snd_2Wq9rT4bLx",
    "recordId": "rec_3Ab9xK2mQ7"
  }
}

​

messageId is a tracking id

​

Worth knowing

• An open is a loaded image. Mail clients and privacy proxies that fetch images automatically count as opens, sometimes before anyone has looked at the message.
• Every load fires. Opening the same email three times delivers three events. Deduplicate on messageId if you only want the first open.
• Blocked images mean no event. A recipient whose mail client does not load images never fires it, even after reading the email.
• Only automated sends are tracked this way. Mail sent from the inbox composer shows read receipts in the app and does not fire this event.

​

Example

custral.on("email.opened", async (event) => {
  const {messageId, recordId} = event.data;
  if (!recordId) return;

  // Count the first open per send only.
  const firstOpen = await cache.add(`opened:${messageId}`); // false if already present
  if (!firstOpen) return;

  await scoring.bump({recordId: String(recordId), signal: "email_opened"});
});