In order to retry an inbound message that timed out, take a look at the Postmarkapp API documentation here.

First, we need to get the server API token that can be found on the credentials page by going to <your server> > Credentials.

Second, we need to get the message IDs which is the hash looking thing in the message URL: https://account.postmarkapp.com/servers/{SERVER_ID}/messages/{MESSAGE_ID}?from=outbound

Finally, we can use curl to retry the message:

  curl "https://api.postmarkapp.com/messages/inbound/{messageid}/retry" \
  -X PUT \
  -H "Accept: application/json" \
  -H "X-Postmark-Server-Token: {API TOKEN}"