> Report the output from "telnet postfix-ip-address 25" from a
> different machine on your local network.
> The output from the internal address is the 250 greeting banner
> and using the external IP is could not open connection : connection
> failed Gary
This confirms that Postfix accepts network connections, and
that the problem is outside of Postfix.
It could be any of:
- Incorrect default route configured on the Postfix host
- Incorrect firewall configuration on the Postfix host
- Incorrect LAN router configuration (NAT/forwarding)
- Conflict with ISP-side configuration
This is a matter of systematic trouble shooting, or random experiments
and dumb luck.