Well, give the ricker hack a try.
Will do but I want to understand it a bit better before I do.
Of course. Therefore the question I posed below.
Is that sendmail box also the mx for the domains concerned?
Currently yes but I will be changing the MX for the one domain that I want to route from the development system to the production system. Now that we have moved the production systems to a co-location facility I am trying isolate the two environments as much as possible and moving the one domain name over is just one part of this. Part of the problem here is that we will be retaining sales/support staff at the our development offices (no mater how hard I tried I just could not squeeze them into that half-rack cage).
If the box is the also the mx for the domain for which you want to do special routing, I believe there will be a problem if you apply that sender_based_routing patch. They cannot share the same mailertable lookups. Another table lookup needs to be defined for sender_based routing.
I will see if I can cook up something on a Centos 4 box.