How do I prevent emails from being sent?

Good Day,

I  am currently busy with a large restructuring of work items in RTC. I need to ensure that users do not receive notifications for these changes. No matter what I do to test, emails are still being sent. I have tried all of the below with no success:

1) Disable email notifications, make changes and enable again.
2) Disable email notifications, make changes, restart Jazz and enable email notifications.
3) Disable email notifications, make changes, add a dummy smtp server, enable notifications, wait an hour and add the correct smtp server.

Is there any other way I can prevent notifications from being sent?

Thankyou,
Regards,
Michael.