Forwarding and the from header...

Hi,
        When I forward mail mail from computer A to computer B using the
recipe 

  :0
  ! $MY_ADDR

then the mail goes to computer B but the "From " header is rewritten to show
that it came from me at computer A.  Is there any way to get it to not 
rewrite the "From " header?  This is kind of annoying on computer B because 
I can't tell in the procmail log where the messages come from.  I'm sure
there is something simple I can do with formail, but my attempts haven't worked
so far.  Any ideas?

Thanks

-- 
  Matthew Harrell                          Any sufficiently advanced technology
  Simulation Technology Division, SAIC      is indistinguishable from a rigged
  mharrell(_at_)std(_dot_)saic(_dot_)com                     demo.