I just installed a SonicWall for our server environment. While most of the traffic is inbound, we do operate an email server that both sends and receives email. I was surprised to discover that this server appears to the world to be sending mail on the firewall's address. Inbound mail is accepted on it's native address. This is causing problems with reverse DNS configuration.
In our current configuration we are using the IP addresses provided by our ISP on the servers so we didn't configure NAT. So if this server has a native address of say 18.104.22.168, I want outbound mail to be coming from that address rather than 22.214.171.124, the address of the firewall.
Can anyone help me to configure the Sonicwall to accomplish this? Do I need a NAT rule that translates 126.96.36.199 to 188.8.131.52?