You can create a batch file to query each filespace for pst files, and
redirect the output
to a text file. You can then import the text file into Excel, using fixed
width, and separate
the output lines into separate fields. You can then sort by date backed up
to find old files
no longer accessed or by size to find out who the pack rats are.

To create the batch file:
If you pipe the output of a q filespace into a files, then open the files
with a word processor,
and creatively use search and replace to add the proper commands to the
front and back
of each filespace, It's pretty easy and quick and easy to create.

cd\tivoli\tsm\baclient
dsmc q backup -nodename=XXXX  '{\\XXXX\d$}\*.pst' -subdir=yes
>c:\out\maillist.txt
dsmc q backup -nodename=XXXX '{\\XXXX\e$}\*.pst' -subdir=yes
>>c:\out\maillist.txt
dsmc q backup -nodename=XXXX '{\\XXXX\f$}\*.pst' -subdir=yes
>>c:\out\maillist.txt
dsmc q backup -nodename=YYYY '{\\YYYY\d$}\*.pst' -subdir=yes
>>c:\out\maillist.txt
dsmc q backup -nodename=YYYY '{\\YYYY\e$}\*.pst' -subdir=yes
>>c:\out\maillist.txt
dsmc q backup -nodename=YYYY '{\\YYYY\f$}\*.pst' -subdir=yes
>>c:\out\maillist.txt

The only problem is that you need to enter the password for each node. If
you use
password access generate, you will only need to do it once, or you can code
the
passwords into the batch files.