Permanently remove all deleted content from PST and OST files

By default, a small percentage of deleted data is not overwritten in Outlook PST and OST files. By enabling this setting, all deleted data in PST and OST files is overwritten when users exit Outlook.

Supported on: At least Windows 7
Registry Pathsoftware\policies\microsoft\office\15.0\outlook\pst
Value Namepstnullfreeonclose
Enabled Value1
Disabled Value0


Administrative Templates (Computers)

Administrative Templates (Users)