Allow Outlook Pst to Grow or Not Grow

If you want to lockdown or unlock an outlook PST file, go into regedit and find pstdisablegrow key. 
Set to 1 to disable growing, 0 to enable.

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Policies\Microsoft\office\14.0\outlook\pst]
"pstdisablegrow"=dword:00000001