Forum Discussion
How to merge 2 Exchange 2016 organizations
- So, compB's MX points to compA's organization; configure compB as an internal relay domain in compA, en configure a send connector for the respective domains pointing to compB's endpoints. If you have mail-users post-migration in compB (eg mailboxes moved from compB to compA), make sure you set targetAddress to a domain uniquely defined in compA (eg. when rebranding set to compA address). This, to prevent you having 2 locations with disjoint populations requiring internal relay for that domain pointing to each other (with bouncing NDRs). Alternativelt, introduce a mail routing domain - similar to Office 365 - such as mail.compb.com, which is an accepted domain in compA, internal relay in compB and set targetAddress in compB to those entries.
Are you aware of possibilities to manage two Exchange organizations from single EAC? I do not know such a possibilities. And I'm assuming your both organizations are on-premises only, and no hybrid setups at all?
So before giving any better deeper answers, it might help if you share a bit your thoughts about the goal? Do you expect to keep these organizations always separated or are you planning to merge them? I'm asking this, as your latest comment confuses me a bit. If you do merge you need to move all (relevant) mailbox data before you can remove the other organization. When you mentioned about your worries with amount of data move, there is possibility to move mailbox with parameter -CompleteAfter. That can be used to move mailboxes almost completed. It is kind of replicate mailbox to other site wiht available bandwidth. And then, when you and user is ready, finalize the move.