Turn off Send and Track feature

Category

User Configuration > Administrative Templates > Microsoft Outlook 2016 > Outlook Options > Preferences > E-mail Options > Tracking Options

Scope

User

Registry Key

HKCU\software\policies\microsoft\office\16.0\outlook\options\flagging

Description

By default, users can flag an e-mail that they send to help them remember to follow up on it later. The flag is not sent to the recipient. By enabling this setting, this feature is turned off.