Hey @Inge25557 - great question! Cancelled meetings are not automatically deleted from O365/Outlook Calendars (or Google Calendar, for that matter). You have to “delete” them to see them vanish all together. That said, if an invitee cancels a meeting that should be that - deleting the event from your connected calendar should not result in their being sent another notification. However, if this is taking place it would be something coming from your calendar and not Calendly, so I’d suggest you reach out to Microsoft support to inquire about what might be going on there!

To cover your bases, check to see if “sync cancellations” is toggled on by going to your Calendar Connection page > check for conflicts > “edit” - this will ensure when you cancel a meeting via your calendar it’s also cancelled in Calendly. 

I hope this helps!