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Support Article

Unable to locate original subject in DSN



Unable to locate the original subject in Delivery Status Notification (DSN) and the original thread topic headers.

Error Messages

Not Applicable

Steps to Reproduce

  1. Open the generated email listener.
  2. On the Process tab, select the Process DSN option.
  3. Open the generated service rule and select the Request tab.
  4. Add a data mapping row in the Message Header section for the thread-topic message header.
  5. Map it to parseThreadTopicHeader Rule-Utility-Function and enter the .pyInboundEmail property as the Map To Key.
  6. Save the listener.

Root Cause

DSN processing depends on the mail server.


Here's the explanation for the reported behavior:

In DSN, thread-topic mapping depends completely on the email server.
In case of Gmail, the thread-topic has the classname and the work-ID; while in Outlook, the thread-topic is just the subject of the failed email. It depends on how the email server perceives and processes the DSN message.


Published August 24, 2018 - Updated October 8, 2020

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