[Exim] Specifying outgoing interface

Hello,

i've got a problem with my exim 4.3.
My Server has bound 3 IP-adresses to its eth0, which is also the connection to the
rest of the world.
But (!) I yust want to use 1 special ip-address for outgoing connections. I know (and
did so) how to configure the "local_interfaces" in my config. With netstat I can see
that exim listens on those ip-adresses, but does not use one of this ip-adresses for
outbound connections to send mail to next MTA.
I already tried to use the "-oX" command line options, but here I can only specify one
IP and I really need at last two IPs (always including 'localhost').

Maybe someone can help me out of this trap :-)

thanx
bernhard