Layer 7 Load Balancer

[Fernando Gozalo]

> Yes, you're true for the ip level. It's why I'm looking for a layer 7
> (application level) solution. For instance, I'm using postfix not
> sendmail.
>
> Have you a postfix based solution ?

Have a look to relay_domains and transport_maps parameters. And this for
reference:
http://www.postfix.org/STANDARD_CONFIGURATION_README.html#firewall

Regards.
Fernando.