Primary and Secondary Servers

This might be a stupid question so please bear with me.

I want to setup 2 MIAB boxes mailservers with MX 10 and MX 20 for redundancy.

What is the best practice to do this. It seems to me like MIAB is setup to be a single box with no failover mail box?


While this could technically be done, I personally do not recommend it.
What might be the reasons that you’d be considering this?