[exim] ACL weirdness?

Hey guys,

I have an ACL which I'm using to effectively block some of the .PDF
spam. I've added a list of whitelisted addresses to the ACL but Exim
doesn't seem to be taking note of them. Is something wrong with my
ACL, or am I missing something here?

My ACL:

   deny message    = $found_extension file matches current SPAM trends.
        condition  = ${if <{$message_size}{20k}{1}{0}}
        demime     = pdf
        senders    = !lsearch;CONFDIR/white.list

CONFDIR/white.list contains:

php.co.uk: *
dejagerinvestments.co.za: marinus
itax.co.za: itax
mettis.co.za: *


Yet, for some reason...

2007-08-14 10:21:36 1IKreg-0003Xs-7P H=www32a.your-server.co.za
[196.7.147.32] F=<Helpdesk@???> rejected after DATA: pdf
file matches current SPAM trends.

Any help would be appreciated.

Thanks,
Marc