"old" data files?

[Jerry M. Keller]

Jerry Keller writes:
I have been a Powermail user for a short time and have just noticed while
looking through my powermail folder, that some of the files have
duplicate files that have the same name, but followed by the word "old",
such as "address data base" followed by another file named  "Address
database old" . My question is, do I need both these files or can I trash
the "Old" versions?
Thanks 
Jerry