When a task in TAC is scheduled to run at different intervals of time, if any misfired event triggers, the notification mail is not sent exactly at that point in time. Instead, notification mails for all the misfired events will be sent at once.
The first run will be OK, but when the Job starts again, you will receive 10 mails at once with misfired notifications. This creates a big problem, as 4000 to 5000 emails are sent at a time when the tasks are encountered with misfired events.
Notification email should be sent exactly when the misfired event is triggered, or only one email should be sent specifying that the misfired events occurred. There is no such control, even to stop sending all emails at once.
The behavior is considered to be bug in the product (TMC-11779).