mailman location spoofing

[Robin Becker]

I have setup mailman at x.co.uk for accessibility/control reasons and it
all works fine. Our principal web address is not x.co.uk, but x.com and
it's possible to divert mail to the lists at x.com to lists at x.co.uk. I
would like to know if there's an easy way to spoof the return address
information in mailman or if that makes sense? I know that the web side
cannot in general be moved unless we run mailman on the x.com server.
-- 
Robin Becker