[Exim] host_accept_relay not working.

hi,

In my exim.config I have (exim 3.3):

host_accept_relays = x.y.z.w : *.myDomain.com : a.b.c.d : 192.168.0.0/24

and

host_lookup = !192.168.0.0/24 : 0.0.0.0/0

But all 192.168.0.x IPs are looked up, so I have had to add them ALL to
the /etc/hosts file. Any ideas why?