I have LXC container with mail server and "dedicated" IP address.
"Dedicated" means that 25 and 110 port of the IP address are forwarded to 25 and 110 port of the container. This is done with iptables.
Let assume internal address of the container is 192.168.0.5 and public address is 126.96.36.199.
Let also assume the server has one LAN adapter "eth0" with one main IP (188.8.131.52) and several additional IP's "eth0:0" is 184.108.40.206
When mail server sends email, the email is send from main IP of the server.
How can I change this behavior and make all outgoing traffic to be via "220.127.116.11"