[Exim] .forward woes

Hello, could you pls help a newbie? How can I get Exim to
delete bounced emails? I'm trying a .forward file in my
home directory, but Exim ignores it. Here's the .forward
filter and the exim.conf file.

# Exim filter <<== do not edit or remove this line!
  if $header_subject: contains "Mail-Delivery Failure" or
     $header_subject: contains "Returned Mail" or
     $header_subject: contains "Undelivered Mail" or
     $header_subject: contains "Returned to Sender" or
     $header_subject: contains "Mail delivery failed"
  then
     seen finish
  endif

# Director
userforward:
driver = forwardfile
file = .forward
no_verify
no_expn
check_ancestor
filter
file_transport = address_file
pip_transport - address_pipe
reply_transport - address_reply

What is wrong?

thanks