I have been assigned to the task to update our company's exhcnage 2016 server.
I found out that is running the RTM version without a single CU update.
I am brainstorming how will the best way to to the update, to be safe and limit downtime.
So i am thinking couple scenarios which im not sure if are viable
Build a new exchange 2016 server with CU 12 and migrate over.
Does the old server needs to be at the same CU to do this scenario?
Running adprep - forestprep will it break up the old exchange server?
In place upgrade old server directly to CU12? i know its risky and requires lots of downtime
Build a new exchange 2019 server migrate over.
Does the old server needs to be updated to a certain CU level in order for this scenario to work?
Any help would be appreciated