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Common Issues

Symptoms: Emails are not being delivered through PostmarkChecklist:
  • Verify your Postmark Server API Token is valid
  • Ensure the TPSP is active and a Message Stream is selected
  • Confirm you are sending with tpspTemplate (required for Postmark)
  • Confirm ippool points to an IP Pool that routes to your Postmark provider
  • Review SendPost event logs for errors
Test Your Token:
curl -X GET "https://api.postmarkapp.com/server" \
  -H "X-Postmark-Server-Token: YOUR_SERVER_API_TOKEN"
If this returns 401, your token is invalid.
Symptoms: Emails are sent but opens/clicks/deliveries/bounces not showingChecklist:
  • Verify the webhook is registered in Postmark (SendPost creates it at TPSP creation)
  • Check webhook URL is https://api.sendpost.io/tpsp/postmark/account/{account-id} (or your ApiUrl equivalent)
  • Ensure the webhook is for the same Message Stream you use for sending
  • Confirm the URL is reachable from the internet (no firewall blocking Postmark)
  • Wait a few minutes (events are batched for processing)
Verify in Postmark:
  1. Go to Postmark → Server → Webhooks
  2. Confirm a webhook exists for your Message Stream with the SendPost URL
  3. Verify triggers include Open, Click, Delivery, Bounce, Spam Complaint
Symptoms: Bounced emails not reflected in analyticsCheck:
  • Hard bounces (TypeCode 1 / HardBounce) → PMHardBounced (72)
  • Other bounces → PMSoftBounced (73)
  • Ensure Bounce trigger is enabled on the Postmark webhook
Error CodeMeaningSolution
401Invalid or missing Server API TokenCheck Key/Secret for the TPSP; regenerate in Postmark if needed
422Invalid payload (e.g. From/To format, missing required fields)Fix request (e.g. include tpspTemplate, valid From/To); no retry for same payload
429Rate limitSendPost retries automatically; consider increasing limits or throttling
5xxPostmark server errorSendPost retries; if persistent, check Postmark status
Error: Send fails when routing to PostmarkCause: Postmark sending in SendPost uses the Templates API; tpspTemplate is required.Solution: Always include tpspTemplate (Postmark template alias) in the request body when the email is routed to Postmark (e.g. via ippool pointing to Postmark).

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Getting Help

If you’re still experiencing issues:
  1. Check Logs: Review detailed event logs in the SendPost dashboard
  2. Contact Support: Reach out to SendPost support with:
    • Your account ID
    • TPSP ID
    • Message ID (if available)
    • Error messages and timestamps
  3. Verify NSQ: Ensure the topic tpsp_webhook_postmark receives messages when Postmark sends webhooks; batcher and worker should process them and store events in ClickHouse

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FAQs

Yes. Create a separate TPSP for each Postmark server (each with its own Server API Token and Message Stream). Each will have its own webhook and configuration.
Yes. The Server API Token is stored as the provider Key/Secret and is not exposed in logs or API responses.
Yes. Use IP Pools to route a percentage of traffic through Postmark and the rest through SendPost infrastructure.
Postmark may retry webhook delivery. Events will be processed once connectivity is restored.
Postmark requires a Message Stream for both sending and webhook registration. The stream you select at setup is used for all sends and for the single webhook SendPost creates.
No. Postmark TPSP setup only needs the Server API Token and a selected Message Stream. You still whitelist your sending domain in SendPost for deliverability.
Events are typically processed within a few seconds of being received from Postmark (webhook → NSQ → batcher → worker → ClickHouse).
SendPost does not impose hard limits; your Postmark plan limits apply. Configure throttling (e.g. Max Sends Per Hour) to match your Postmark capacity.