Tell ActionMailer to use a specific IP address to send

Hello everyone

Ubuntu 8.04 64bit Rails 2.3.2

I have multiple IP addresses on a server, with an alias setup to handle
it

eth0:0 IP 1.1.1.2
eth0 IP 1.1.1.1

We run one app on one IP, and the other on the other IP(ssl
restrictions)

The app on 1.1.1.1 is allowed to send mail through our gateway.

What’s happening is that our Gateway is blocking emails from the app
that is setup to run on 1.1.1.1 saying that the email came from 1.1.1.2

Is there a way that I can tell the ActionMailer to send from 1.1.1.1?

Any help, greatly appreciated.