[Exim] Newbie : . forward filter not working

We have installed Exim 3.3 on a FreeBSD. I tried to test an exim filter on a
.forward file.

I have uncommented the 'filter' option in the userforward director in the
config file.

The config file has the following settings:

userforward:
driver = forwardfile
file = .forward
no_verify
no_expn
check_ancestor
filter
file_transport = address_file
pipe_transport = address_pipe
reply_transport = address_reply

The .forward file contains:

# Exim filter

if error_message then finish endif
if personal then deliver antispam endif

When I send to the user with the test .forward filter, I get these messages:

/home/test1/.forward: line 2: if error_message then finish endif... User
unknown
/home/test1/.forward: line 3: if personal then deliver antispam... User
unknown
/home/test/.forward: line 3: if error_message then finish endif... User
unknown
/home/test/.forward: line 5: if personal then deliver antispam... User
unknown
/home/test/dead.letter... Saved message in /home/test/dead.letter

It seems that the exim filter script is not being recognized. Does any have
any idea on fixing this error?

Thanks a lot.

Abraham Tomas
tomas@???