Using older versions of Outlook for Mac for personal email and calendar
Hello Randy954,
I tested on my side based on your description, when I edit an event on calendar, the attendees (no matter who replied “yes” or “decline”) received modified events. No one received cancelation emails. Given this situation, if you use Outlook for Mac client, I would suggest you try to edit events on Outlook Web App to rule out Outlook client problems.
If the problem persists on OWA, as your situation is not the same as this thread, to better help you, we strongly recommend you post a new thread on our forum with your detailed information. There will be another engineer help you troubleshoot your problem more accurately. This can help other community members who have similar problem easily view this thread either.
We truly appreciate your understanding and cooperation.
Best Regards,
Sylvie