procmail with mail user

[dougw2112]

on other Unix's I was able to use the following to sort mail:

formail -s procmail procmail.receipe < mboxmailfile

this would sort my mail for me, works great.

How do I accomplish this with a Plesk mail user? I realize I'm using qmail, but I have some mboxes that I want to resort? thanks...

dougs