User Configuration > Administrative Templates > Microsoft Outlook 2016 > Miscellaneous > PST Settings
User
HKCU\software\policies\microsoft\office\16.0\outlook
This policy setting allows you to specify a different folder location for Outlook Data File (PST) files on user computers. If you enable this policy setting, you can specify a location for PST files on user computers. If you disable or do not configure this policy setting, PST files are located in: %USERPROFILE%\Documents\Outlook Files\ on user computers.