Is it possible??

I already asked this question from my other internet account but was 
concerned whether it was going to make it because the universitys mail 
was down so here goes again.  

Is it possible to have all incoming mail to pass through procmail and be 
processed before going to the users normal mailbox.  Or do I have to copy 
.forward to 800 accounts.

If it is possible please point me in the right direction as I am somewhat 
baffled with the mail system on our unix host.