Forum Discussion
How to merge 2 Exchange 2016 organizations
- Apr 01, 2019So, 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.
Merging is the ultimate goal, but we are trying to avoid a hard cut. It would be
disruptive and time consuming so we'd like to move mailboxes over one at a time
while still maintaining mail flow.
The problem that I see right now is Company B's MX record will need to point to Company A's receive connector. When we do that, and we start moving mailboxes between servers, how do we route mail to the correct mailboxes for users in the Company B email domain?
if we migrate mailboxes one at a time, the email domain for Company B would need to exist in both organizations. How would mail get routed to the proper mailbox/server in that case?
Have you read these:
- Moving Mailboxes Between Exchange Organizations
- Easy cross-forest migrations on Exchange Server
- Prepare mailboxes for cross-forest move requests
Keep in mind, if you have Skype in use both sites, then that makes this a bit harder as Skype does not support cross-forest migration.