AxonEngine8 : Could not send new task notification mail of task {0}

Surachet

Hello AxonIvyTeam,

I implemented a process to generate many tasks and assign these tasks to the responsible person. and then system tried to send many "new task notification" at the same time. only some emails were sent and got a lot of this error message back.

"2022-08-17 07:04:53.936 ERROR [ch.ivyteam.ivy.system.email.internal] [ivy immediate job pool-thread-65] [executionContext=SYSTEM] 
  Could not send new task notification mail of task 123,456"

Questions:

I would like to know the root cause, How can I find the real error message? log with DEBUG mode?
Is there any process to resend the notification for this case?
If it would be a case of emails limit exceeded/spam filter, would it be possible to configure like "max emails per sec" on the engine level?
With my current implementation, I received "new task notification" twice for the same task id and I could not find the root cause. Could you please explain what is a logic to trigger this email notification? Can i find this queue job in DB table?

Thank you,
Surachet

Reguël Wermelinger

Hey @Surachet

The log message you are stating takes a generic 'RuntimeException' as argument. So, the root cause should be directly visible just under that log you shared here.
I think this immediate Task notification will not be repeated. The error is generic, so very likely it will occur again if it would be retried. However, if you have daily task notifications mails on too, the user can see this task in there.
There is no mechanism at work to slow down the mail sending job, in order to avoid running into rate-limits.
There is no way to trace or trigger the TaskMail jobs in the database. Maybe you got the same task notification via different e-mails you collect in a single inbox?

From ivy 9.1 on-wards you can inspect the mail sending work via JMX. https://dev.axonivy.com/doc/9.3/engine-guide/monitoring/jmx.html
For instance with JVisualVM, you can inspect the email server. Numbers on sent mails or errors that occurred will be exposed at runtime.

Peter Hochstrasser

If no task mail is sent, we see that often, the StandardProcess.MailNotification entry in app.yaml does not contain the mail send process. This may result in a HTTP 500 error being logged whenever the taskmail should be sent: Because the engine does not know the mailnotification process it produces an internal error (HTTP 500).