Hi, I hope this letter finds you well,
I have Postfix behind NAT, and added one failover IP to the main router.
I wanted to "get by cheaply" by just doing something like
iptbales -t nat -I POSTROUTING -p tcp --dport 25 -j DNAT --to <backup ip>
on the firewall machine.
So, all well, the only problem is that Postfix in this case has a wrong HELO compared to the rDNS that I have defined
for the <backup IP>
It does throw a warning that the <backup IP> doesn't resolve to it's hostname, but I'm not sure if I can define some
kind of helo_host_maps ;) to resolve this.
At this point, I wouldn't mind if someone pinpoints me to the right direction.
Thanks, and all the best,
Istvan
