[exim] testing to/from IP/port combinations

I've got a good set of simple tests to confirm that my exim config is
sensible, that consist of throwing a whole load of invocations of swaks
and checking whether they get accepted/denied correctly.

I can control which IP/port on the server I connect to just fine (i.e.
to differentiate between the public IP and localhost where the webmail
comes from); but I can't see a way of "faking" the IP address I'm
connecting *from* (especially useful for testing dnslists/RBLs)

'exim -bh 127.0.0.2' is good for that, as it triggers the dnslists
checks properly, but I also have an ACL looking for $received_ip_address
and $received_port (so that I can detect the submission port, for
example), and '-bh' doesn't seem to populate these variables.

So, can you please tell me how to do this correctly, or share other
stories about how you do testing?

-jim