Linked Mailboxes on Exchange Online

Question

Hi,

We have an account-resource forest deployment type, where the exchange organization are in the resource forest and all the mailboxes are linked to they master accounts that's are hosted on the account forest.
We are trying to make this linked mailboxes visible on Exchange Online, like a mailuser, but in our lab was not possible.
(We don't want to migrate these linked mailboxes, we want to make and hybrid deployment)

And whenever we enable the licence of the Exchange Online to the linked user's other separate mailbox is created (usermailbox).

When we see the details of the running profiles on the sync service, we found that the projections are not replicated to the tenant.

Trying all the steps on this article, we have the same result, the linked mailboxes are not synced to the tenant.
https://jaapwesselius.com/2018/04/26/exchange-resource-forest-and-office-365-part-ii/

We trying also to change the linked account on the resource forest (change the password and enable it), change the running profiles to accept disabled accounts on the sync services, all this without luck.

Docs of Azure AD Connect say that this is possible but we are stuck on this point
https://learn.microsoft.com/en-us/azure/active-directory/hybrid/plan-connect-topologies#multiple-forests-account-resource-forest
https://learn.microsoft.com/en-us/azure/active-directory/hybrid/tshoot-connect-objectsync#linked-mailbox-issue

Resource and Account forest Azure AD Connect is configured whit this option and the azure login att is the mail.

Can anyone have an idea why this happens?

Thanks in advance for your help.

Regards -

Answer 1

Hi @DaroUY

Do you mean you meet the issue users not synced here? Please correct me if I have any misunderstanding about your question.

If this is the case ,first make sure we select the right Domain/OU filtering options for both Forest (the containers containing the user accounts in the Account Forest and the corresponding Mailboxes in the Resource Forest)

Here is also an article tells about how to Migrate Your Linked Mailboxes
Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

A different scenario is introduces here: a client who had a mixture of linked and non-linked mailboxes, so in this case, we couldn’t match users on the ObjectSID and msExchMasterAccountSID attributes. Instead, we chose to match users using the SamAccountName and MailNickName attributes. In most scenarios, user objects in each forest will have the same value for these attributes, so matching accounts on these attributes is the next best option. If this is not the case in your environment, you will need to select another attribute to match your users on. You will also need a process in place to populate this attribute correctly across the AD objects in the two forests.

In addition, if your issue is related to the AAD not sync, I would suggest you refer to the trpubleshooting step here: Troubleshoot an object that is not synchronizing with Azure Active Directory

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Answer 2

Hello all,

is there still an update here, because I have exactly the same problem and I just can't get on...

Greetings
Nip_0