DUAL WAN - How to get two Email Accounts Working

RouterOS Beginner Basics
1

I have a failover dual wan setup (recursive). Main WAN distance=3, Secondary Wan distance=10
I have email from the secondary WAN via ROUTE to destination IP and gateway IP and distance = 1.
(I gather the SMPT resolves to that IP address and the route is established).

NO USE OF PORTS at all.

Now however, I wish to also use the email of the primary EMAIL service.
What is the best way to proceed.
a. use ports in firewall rules?
b. make another route rule for the destination IP of the primary email server, but what distance??
c. ???

2

And what is it exactly what you want? What’s “email from the secondary WAN” and “email of the primary EMAIL service”? Is it one server that you want to use over both connections (but how would you tell router which one)? Or are those two different servers? In that case, doesn’t the one without specific route use default one already?

3

Yes, my bad, it was my email setup that was wrong. The primary works now without any other settings.
Cheers and Merry Xmas Sob