Routing Outbound Traffic over specific IP

Let me start by giving my usage scenario followed by my question.

We have two Peplink Balance 580’s. We have multiple wan circuits. On one of our circuits we have 2 class C ip address in addition to the static IP for the WAN circuit. Our Wan IP is X.X.192.210 and we have X.X.193.1/24 and X.X.211.1/24.

Our mail server is on ip 193.2. We have outbound rules set so all outbound smtp traffic goes out over the WAN circuit with those IP address.

Is there anyway to configure it so all the SMTP traffic goes out over the ip 193.3 vs the 192.210? This way the RDNS will match that of the perimeter mail server?

Thanks in advance for any help you may have!

The Balance if deployed in NAT mode can do a 1-1 NAT mapping from 193.3 to your internal email server. The email server can use 193.3 for both inbound and outbound traffic if you want.