Exchange hybrid deployments with multiple forests and moving mailboxes

pazzoide76 281 Reputation points
2021-11-22T09:05:25.817+00:00

Hello,
I would like to implement an Exchange hybrid deployments with multiple forests.
Currently there are two forests company a and company b that are in trust with each other and each has an exchange server.
An exchange hybrid has already been configured for company a and now I would like to hybrid also with the exchange of company b. It's possible?
Once both exchanges are hybridized, since I would like to dispose of the forest of company a, I would like to ask if it is possible in some way to link the mailboxes of company a to the users of company b.
I would like to do this as I would like to unify all users and mailboxes under the company forest b.
It's possible?

Thanks

Greetings

Microsoft Exchange Hybrid Management
Microsoft Exchange Hybrid Management
Microsoft Exchange: Microsoft messaging and collaboration software.Hybrid Management: Organizing, handling, directing or controlling hybrid deployments.
1,240 questions
Microsoft Exchange Online Management
Microsoft Exchange Online Management
Microsoft Exchange Online: A Microsoft email and calendaring hosted service.Management: The act or process of organizing, handling, directing or controlling something.
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  1. KyleXu-MSFT 25,616 Reputation points
    2021-11-23T01:56:36.447+00:00

    @pazzoide76

    Exchange online hybrid with two forests is supported. But you need to change the topologies of AAD Connect first:
    151632-multiforestsingledirectory.png

    About link mailboxes in hybrid, you could have a look about this article: EXCHANGE RESOURCE FOREST AND OFFICE 365 – PART IV

    Personally, I suggest you merge the two forests, which will facilitate the management and deployment of hybrids:

    • After adding domain B in forest A "Active Directory Domain and Trusts", you will could use domain B as logon name in forest A.
    • Then, add the domain B as an accepted domain in forest A Exchange, you will could use domain B as email address for forest A mailbox.

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