IntegrationsTutorial

Postmark

Transactional sender and server-token readiness.

Integration

Postmark

Confirms transactional sender readiness.

Launch email fails quietly when the server token is valid but the sender signature is still unconfirmed—welcome emails, receipts, and alert messages never leave the queue. PreFlight verifies your server token, reads sender signature status, and flags unconfirmed senders before production mail depends on them.

Requirements

What PreFlight checks

| Probe | What it proves | | --- | --- | | Server token auth | The Server API Token authenticates against Postmark. | | Sender signature status | The configured sender is confirmed or the domain is verified. | | Unconfirmed sender flag | Launch-blocking senders are surfaced before you ship. | | Delivery readiness | Transactional mail can leave Postmark from the configured identity. |

Failure guidance

| Symptom | Fix | | --- | --- | | Invalid server token | Copy the token from Postmark → Servers → API Tokens. | | Sender unconfirmed | Complete the Postmark confirmation email for the sender signature. | | Domain not verified | Add DNS records for domain verification in Postmark before launch. | | Wrong server | Confirm the token belongs to the server tied to your production templates. |

Dashboard setup

Open Integrations → Postmark in your PreFlight project. Paste the Server API Token and sender email from Postmark. Add the Sender Signature ID or verified domain identifier. Run Pre-Flight Check and confirm sender status is confirmed or domain-verified.