When someone bounces, marks an email as spam, or unsubscribes, Postmark can tell your website. VisionScaper then stops mailing that person.

• Postmark is set up (see “Get your Postmark Server API token”).
• A Broadcast stream exists.

1. In WordPress open Settings → VisionScaper Marketing.
2. Find the row Postmark webhook. It shows an address that ends with /wp-json/dreamscaper/v1/mkt/postmark?k= and a long random key. Click the box and copy all of it, including the key after k=. The key is VisionScaper’s own secret and is created automatically.
3. In Postmark open your server, then your Broadcast stream, then Webhooks, and add a webhook. That is the path VisionScaper’s page gives. The button text is not verified.
4. Paste the address.
5. Tick Delivery, Bounce, Spam Complaint and Subscription Change.
6. Use Postmark’s verify option. Postmark says it tests the address for each enabled event and expects a 200 reply.
7. Save.

(Per the plugin’s description of the webhook handler. Exact status wording not verified.)

• Postmark does not sign webhooks. Its page suggests using a password in the URL, limiting by IP, and checking payloads. VisionScaper uses its secret key in the address, so keep the address private.
• Do not paste the address in public places. Anyone who has it can send fake events.
• Postmark also offers Open, Click, Inbound and other events. VisionScaper’s page asks only for the four above.

• Postmark says the webhook failed verification. The site is not public, or the address was cut off before the key.
• Unsubscribes do not register. The webhook was added to the wrong stream.

• Postmark, webhooks overview: https://postmarkapp.com/developer/webhooks/webhooks-overview (read 2026-10-15)
• Plugin: includes/marketing-admin.php; includes/marketing-public.php.

• Get your Postmark Server API token
• Get your Resend API key
• Get your SendGrid API key