InboxMon

ESP setup

Postmark — add and edit

Create an InboxMon card, add the webhook on the Postmark server that actually sends, then edit that webhook if the URL changes.

InboxMon does not send campaigns. You send with the ESP. InboxMon only receives events on the webhook URL for that connection.

Add the connection in InboxMon

  1. Sign in → Settings → ESP connections.
  2. Provider: Postmark. Sending domain: the From domain (no www, no @).
  3. Optional: DKIM selectors now, or save them later on the card.
  4. Add connection. Copy the webhook URL (includes ?token=). Paste the whole string.

One card per ESP + sending domain. Each extra Add click creates a new URL. Only the URL you paste into the ESP will show Last event.

Add the webhook in Postmark

  1. Confirm the sending domain / signature (Sender Signatures or Domains) until Confirmed.
  2. Open the Server that sends that mail → Settings → Webhooks → Add webhook.
  3. URL = the copied InboxMon URL.
  4. Enable at least Delivery, Bounce, Spam complaint. Add Open / Click for engagement. Subscription change maps to unsubscribe in InboxMon.
  5. Save. Postmark may probe the URL; InboxMon returns 200 only when the token matches.
  6. Optional: set HTTP Auth password to the same token as in the URL.
  7. Send from that same server (UI, API, or SMTP).

DKIM: save the real selector on the InboxMon card if it is not a common guess (pm, dated keys). Then Domains → Check DNS now.

Edit the connection in InboxMon

You cannot rename the provider or sending domain on an existing card. Use the card controls:

  • Copy — same webhook URL. Use this when you need to paste it again into the ESP.
  • Disable — InboxMon stops ingesting. The ESP may still POST; those requests are skipped. Use this for unused duplicate cards.
  • Enable — ingest resumes on the same URL. You do not get a new token.
  • DKIM selectors → Save selectors — for the Domains watchdog only, not for webhook ingest. Gray placeholder text is not stored until you save.
  • Sync ESP data / Sync now — re-runs DNS and anomaly detection on events already stored. It does not pull history from the ESP.

To change the sending domain, add a new connection, point the ESP at the new URL, then Disable the old card.

Edit the webhook in Postmark

Change the InboxMon URL

  1. InboxMon → Copy on the existing card.
  2. Postmark → that Server → Webhooks → open the existing webhook (or delete and add if the UI has no edit).
  3. Paste the new URL, keep the same event types, Save.
  4. Send a test from that server.

Events going to the wrong workspace

The webhook must sit on the same Postmark server you send from. A webhook on Server A never sees mail from Server B. Point Server B at its own InboxMon card.

Pause ingest

Disable the InboxMon card, or delete/disable the Postmark webhook. Extra InboxMon cards: Disable them.

Confirm it works

Send a real message. Within about 30 seconds the card should show Last event, then Overview and Events fill in. Keep the webhook URL private. Requests without a matching token return 401. A full monthly event cap returns 429.

If Last event stays empty

  • Webhook is on the same Postmark server you sent from.
  • This card’s URL (token included).
  • Connection active.