The user could have actually deleted everything in the PST file and not
compacted it. Generally, with a PST, if you delete the data from within,
the space is not automatically reclaimed. You would have to compact it to
reclaim it.
I suggest making a copy of the PST, connecting it to Outlook and compacting
the copy, and seeing what size you end up with then. Or you can try running
the Inbox repair tool (scanpst.exe) on the copy to see what happens to it.
Lucy
