[exim] save command in systemfilter

Hi,
I want to add a new filter which moves all incoming email from x@??? to a
subfolder:
if $header_from: contains "x@???"
then save /home/username/mail/mail/folder
finish
endif
first got error message: "failed to find "adress_file" transport, I changed
transport "address_file" to "adress_file" in (default!) exim.conf and now
got message: user 0 set for adress_file transport is on never_users list
what can I do?

config is exim 4.33, exim runs as user exim an on never_users list
(exim.conf) is only root!