[exim] which IP address will be used

Hi,

I wonder if anyone can point me in the right direction? If I have a
'multi-homed' linux box i.e. with 2 IP adresses and I run Exim on it, which
IP address will it use?

Also, is it possible to set the IP address used by a parameter such as
recipient domain? I'm thinking in the case of a local domain for a remote
office that we have a 'peering' private network set up with. Maybe that's
not a clear example, but could I route ourcompanydomain.com emails through
one IP and everything else through another IP?

thanks...