There is a free utility called "PST19UPG.exe".
One place to find it is:
http://www.securiteam.com/tools/6G00B1F0AS.html
"This utility was originally designed to upgrade the PST
format to version 19. One of its side effects, however,
is that it can strip out the PST password. This can therefore
be used to recover passwords you may have forgotten on
your PST files.
This is a rather advanced tool. If you have any questions
or problems, write back.
NOTE: Does not work for the Outlook 2003 format.
--
Nikki Peterson [MVP - Outlook]
I forgot mailbox.pst password. Can anyone help me out? any
third party tool is available to recover the password?
Regards,
MS