I don't understand what you mean by your first point. The delete button I was talking about is in Outlook running in a browser: https://i.imgur.com/k4ejdw4.png

I don't understand what you mean by your first point. The delete button I was talking about is in Outlook running in a browser: https://i.imgur.com/k4ejdw4.png https://i.imgur.com/k4ejdw4.png Pressing the delete key on my keyboard brings this up: https://i.imgur.com/SBVkpVf.png https://i.imgur.com/SBVkpVf.png Clicking delete doesn't send any notification to the other side, where this account still shows as having accepted the invite (the other side is a different Office 365 organization).