transactional email webhooks

Transactional email webhooks are callbacks your email provider sends to your server when something happens to an email you sent.

Common events:

• Delivered — email reached recipient’s mail server
• Bounced — email was rejected
• Opened — recipient opened the email
• Clicked — recipient clicked a link
• Deferred / delayed — delivery was temporarily postponed
• Spam complaint — recipient marked it as spam
• Unsubscribed — recipient opted out

How they work:

1. You send an email through a provider like SendGrid, Mailgun, Postmark, SES, etc.
2. The provider tracks events for that message.
3. The provider sends an HTTP request to your webhook endpoint with event details.
4. Your app processes the event, updates records, triggers workflows, or logs analytics.

Typical webhook payload includes:

• message ID
• recipient email
• event type
• timestamp
• IP / user agent
• campaign or metadata
• SMTP response for bounce/defer cases

Why they’re useful:

• Track delivery reliability
• Detect bad addresses and suppress future sends
• Measure engagement
• Trigger downstream actions like receipts, reminders, or follow-ups
• Keep your database in sync with actual email status

Best practices:

• Verify webhook signatures to prevent spoofing
• Make the endpoint idempotent
• Respond quickly with 2xx status
• Retry safely on provider side
• Store raw payloads for debugging
• Use event deduplication, since providers may send duplicates

Example use cases:

• Order confirmation delivered → mark notification as sent
• Bounce received → flag address as invalid
• Click on password reset link → audit security event
• Spam complaint → unsubscribe user immediately

If you want, I can also show:

• a sample webhook payload
• how to set up a webhook endpoint in Node/Python
• how to verify signatures for SendGrid/Mailgun/Postmark/SES