Create a "RECEIVED MESSAGE" and a "READ MESSAGE" option in Outlook for MAC like you have in Outlook for Windows.
In Outlook for WINDOWS, there is a function when you are composing a message to require a "MESSAGE RECEIVED" notification and a "MESSAGE READ" notification. I have asked many times that you include this feature in Outlook for MAC. If you do it in Windows version, why can't you do it for MAC?
recall sent messages in outlook for mac