Sean Son:
> In our main.cf file , inet_interfaces is set to all.
Then, Postfix will not bind to one nic. See the inet_interfaces
discussion in the postconf(5) manpages for multi-homed firewalls.
A better solution for multi-homed firewalls is to leave inet_interfaces
at the default value and instead use explicit IP addresses in the mas-
ter.cf SMTP server definitions. This preserves the Postfix SMTP
client's loop detection, by ensuring that each side of the firewall
knows that the other IP address is still the same host.
Wietse
