I have a workflow with a start event of Microsoft Exchange Online Received Mail. The criteria is “Subject contains some key words generated from a program”. The account receives about 10 of these emails per hour.

I can match up the email received time with the instance time for emails that were received shortly before and after this one. But there is no instance in history that matches up with the time this email was received.

The workflow was published many days before this happened, so it wasn’t a case of it being published at the time the email was received.

I checked the Status on Nintex Customer Central and there was no outage at that time. (There was an outage a day before, but it appears that no workflows were missed, they were just backed up.)

What would cause the workflow to not kick off?

And how can I trust that all emails with that subject will indeed kick off the workflow? 

All I can think of for monitoring is somehow query the number of emails in the inbox with the subject for a given day and compare it to a count of workflow instances … somehow…

Thanks in advance for any tips you can provide.