Please enable read receipts in the MAC version of Outlook!
We are happy to announce that this feature is available to all O365 subscription users with 15.35 (170610) or later build.
Please refer to our post for details:
why would this obviously needed feature be left out?
Create read receipt and delivery receipt functionality. It exists in Outlook for Windows/PC -- why discriminate against MAC users?
Halim G commented
Suggest add ability to request a read receipt in Outlook 2016 for Mac (with an Office 365 Business Account).