[Exim] Custom MAPS for RBL

I have been using rbl_domains option.
Working as it should.
I tried using relays.orbs.org and found it way too restrictive.
We were flooded with phone calls.

I see that according the the documentation I can create my own MAPS!
Cool - But I can't find how to do it. Any help would be greatly
appreciated

Regards,
Ed Zimmermann
Network Operations Manager
Internet Specialties West
818.735.3000v
818.735.3004f