Answer
The failure is most likely happening while the system is trying to create the application message itself for the email, which can throw an error separate from whatever the Application Message's own final status later shows. Check the PRINT_JOB_TAB row for that specific print job ID — it frequently holds more of the actual error text than what's visible in the UI — and cross-reference the application server logs for the same timeframe, since the fuller exception detail (including whatever the job status message is only partially showing) usually appears in one of those two places rather than in the Application Message screen itself.