Webhooks

Webhooks let you receive delivery events in real time. Configure a URL in the dashboard and MoSend will POST to it every time an event occurs.

Available events

Event	Description
`email.delivered`	The email was delivered to the recipient's server.
`email.opened`	The recipient opened the email (requires tracking pixel).
`email.clicked`	The recipient clicked a link.
`email.bounced`	The email bounced and could not be delivered.
`email.complained`	The recipient marked the email as spam.

Payload

MoSend sends a POST with a JSON body like this:

{
  "event": "email.delivered",
  "created_at": "2026-04-14T10:24:02Z",
  "data": {
    "email_id": "em_7a3f9b2c1d8e",
    "to": "usuario@ejemplo.com",
    "from": "hola@tudominio.com",
    "subject": "Bienvenido"
  }
}

Signature

Every request includes an X-MoSend-Signature header with an HMAC-SHA256 of the body, using the webhook secret. Verify it before processing the event.

import crypto from 'node:crypto';

function verify(signature, rawBody, secret) {
  const expected = crypto
    .createHmac('sha256', secret)
    .update(rawBody)
    .digest('hex');
  return crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(expected),
  );
}

import hmac, hashlib

def verify(signature: str, raw_body: bytes, secret: str) -> bool:
    expected = hmac.new(
        secret.encode(), raw_body, hashlib.sha256
    ).hexdigest()
    return hmac.compare_digest(signature, expected)