Sending & delivery events

Webhook

An HTTP callback your application receives in real time when an event happens — a delivery, open, click, bounce or complaint — instead of polling for status.

Why webhooks beat polling

Without webhooks, your app would have to keep asking the email API whether each message was delivered. With webhooks, the platform sends an HTTP POST to your endpoint the moment something happens, so you can update records, trigger follow-ups or alert your team in real time.

Handling webhooks reliably

Verify the signature on every request, so nobody can fake events.
Respond with a 2xx quickly and do slow work in a background job.
Make handlers idempotent, because retries mean you may see the same event twice.
Log failures, so you can replay anything your endpoint missed.

Webhooks in MailCraft

You can subscribe an HTTPS endpoint to any of these events: email.sent, email.delivered, email.opened, email.clicked, email.bounced, email.complained, email.unsubscribed, email.delayed, email.failed and email.rejected.

Each delivery is signed with HMAC-SHA256 over a timestamp and the raw body, so you can verify it and reject stale requests. Failed deliveries are retried five times over about 15 hours, and redirects are never followed, so answer with a 2xx directly.

Let MailCraft handle the details

Authentication, bounces, complaints and suppression are built in. Start free with 3,000 emails a month, no credit card required.

Start free

Related terms

Full glossary