User Configuration > Administrative Templates > Microsoft Office 2016 > Collaboration Settings
User
HKCU\software\policies\microsoft\office\16.0\outlook\options\mail
"Enable ad hoc reviewing": Enables the ad-hoc review feature. | "Exclude author's e-mail in documents": Enables the ad-hoc review feature, but the authors e-mail is not recorded on the sent document. | "Disable ad hoc reviewing": Disables the ad-hoc review feature.