[Exim] Accepting mail from hosts with no reverse DNS

Hi,

at present I'm getting rejects like this:

2002-06-18 07:37:32 connection from [196.26.82.66] refused (failed to
find host name from IP address)

Due to the terrible way the Reverse DNS is setup in South Africa, I
need to be able to accept mail like this.

How do I set Exim 3.3 to do it?

Thanks

Nico