Forwarding mail from one domain to another

[Nutter]

I've got a VPS running RH with a primary domain and three domains that point to it. How can I go about setting it up so anything from one of the secondary domains gets forwarded to the primary? That is [e-mail] goes to [e-mail].

Thanks,
- Ryan

[Nutter]

Never mind, I found it. It's the /etc/vdomainaliases directory.