User Configuration > Administrative Templates > Microsoft Outlook 2016 > Security > Trust Center
User
HKCU\software\policies\microsoft\office\16.0\outlook\security
This policy setting controls whether Outlook also applies the macro security settings to installed COM add-ins and additional actions. If you enable this policy setting, the macro security settings will also be applied to add-ins and additional actions. If you disable or do not configure this policy setting, Outlook does not use the macro security settings to determine whether to run macros, installed COM add-ins, and additional actions.