Exchange server 2010 how to split?

Question

Mail server

Good afternoon, the situation is 1 exchange 2010 server on which there are many domains, the task is to separate one domain, drag it to a separate server, but have one address book.
Tell me if it is possible, if anyone has come across, maybe there is some kind of case?

Answer 1

I didn’t work closely with Ex, but the address book there seems to be built at the AD level.

Answer 2

According to the task of separation, there are several options:
1. Leave Exchange 2010 transit - then make the domains that will be serviced by another mail server External Relay
2. Separate at the level of MX records - two different infrastructures.
Regarding the general GAL - the address book is really stored in AD, in order for it to function - you need to create MailContacts in the domain with Exchange - usually this is done either by a separate application (for example, it can be FIM), or by a script.
There are no other options.