there's an Exchange 2010 running on Server 2008 (R1) that is hosting roughly 300 mailboxes. This entity is going to be split into two separate installations each requiring their own system. At the same time it is high time to migrate to 2016.
After this split, the two systems will still be connected, but eventually I would like to split AD in two alltogether. One will stick with the existing AD, for the other I would love to start with a new domain.
I have never done this. What is the best way to go about this? Create a new domain under the same tree? Can I then install one new VM into the existing domain and one into the new domain under the same tree, install exchange twice, then migrate the mailboxes to their future home?
Is there a way to remove this new domain from this tree later?
Thanks for a rough how-to.