[Exim] Using AMaViS configuration help

Hi

I am installing AMaViS and McAfee for virus scanning and I have a quick
question.

In the README.exim distributed with amavis it states that a new director
should be added to the DIRECTORS section and that order matters, but
then does not say what oorder it should be in.
The other directors I have are system_aliases, userforward, and
localuser.

Where should I put the scanmails director?

Thanks

iain