Permission exist but not work after migrate exchange mailbox to another domain

Question

Hi,

We use ADMT to migrate domain from A to B, and also move the ex2016 mailbox in domain A to ex2019 in domain B.

After move the user mailbox and relate shared mailbox, user cannot access the shared mailbox in outlook. But can use "open another mailbox" in OWA to access the shared mailbox
Checked in EAC console and also PowerShell "get-mailboxpermission", the permission is existed.
If we add the additional mailbox in outlook, the shared mailbox no permission to access.
If we manual remove and add the permission again, the outlook can auto-map and show the shared mailbox correctly

Seems the permission is migrated but didn't work normally. Is it the know issue if the mailbox move from one domain to another domain?

Thanks

Chong

Answer 1

Hi @Chong

I tested in my lab and seemed to have reproduced this issue.

I suppose the cause of this issue is the attribute msExchDelegateListLink which is responsible for automapping, was not migrated either by the Prepare-MoveRequest.ps1 script or ADMT.
Thus the shared mailbox cannot be automapped in Outlook.

But as a workaround, you should be able to add it manually in Outlook:

1. locate File>Account Settings>Change>More Settings>Advanced
2. add the shared mailbox as an additional mailbox
   

You may also remove and re-add the permission to have the attribute added to the account.

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Answer 2

I think your best solution is to remove and re-add the perms. They probably need to set again so Exchange "sees" it.

Answer 3

Problem solved.

It need to include the msExchDelegateListLink attribute during ADMT migration.