Policy
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.
Pack Microsoft Office
Category Microsoft Outlook 2016 / Miscellaneous / PST Settings
Policy ID
9da4c130b9a9 Internal name
L_Permanentlyremovealldeleteditems Registry
Copy registry mappings
HKCU\software\policies\microsoft\office\16.0\outlook\pst\pstnullfreeonclose (enabled) = 1
HKCU\software\policies\microsoft\office\16.0\outlook\pst\pstnullfreeonclose (disabled) = 0 Policy notes
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.