Luca Cazzaniga:
> I'm running postfix on a host behind a firewall which performs a port
> address translation of the port 25 on the inbound connections, whilst the
> outbound connection gets a nat to a extranet address.
> The daemon supplies smtp service for the local network. An intranet dns
> resolves its hostname in a intranet address whilst the same fqdn is resolved
> to the extranet address used for the pat translation via a public dns.
> The extranet address used by the pat is other than the global address of the
> outbound connection.
> I haven't used the proxy_interfaces variable and it seems to be any problem.
> When the proxy_interfaces is necessary?
> Might I set it to the extranet address used by inbound connection?
man 5 postconf
proxy_interfaces (default: empty)
The network interface addresses that this mail system receives mail on
by way of a proxy or network address translation unit.
This feature is available in Postfix 2.0 and later.
You must specify your "outside" proxy/NAT addresses when your system is
a backup MX host for other domains, otherwise mail delivery loops will
happen when the primary MX host is down.
Example:
proxy_interfaces = 1.2.3.4
