User has duplicate mailboxes

Question

We have couple of users whose mailbox exist in both Exchange Online and on-premises.

The New-MailboxRestoreRequest -command restores only one message from the disabled onprem mailbox. How to fix this issue?
User has more than one item in the disabled mailbox:

I tried restoring two mailboxes, both restore requests were able to restore only one item

My requirement is to disable the duplicate OnPrem mailbox on restore it’s contents to Exchange Online mailbox.

Answer 1

@JustinMicheal-7973

The New-MailboxRestoreRequest -command restores only one message from the disabled onprem mailbox. How to fix this issue? User has more than one item in the disabled mailbox:

This command will recover all items from the disabled mailbox. If this command only recover one email from your disabled mailbox, I think you may recover the wrong disabled mailbox(There only exist one email in this mailbox).

You can try to follow this article to restored this disabled mailbox item to a new Exchange on-premises mailbox, check whether there only exist one email in this disabled mailbox.

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There also exist an another improvement plan: before step 3 "Disconnect the on-premises mailbox", you could use New-MailboxExportRequest command to export data from Exchange on-premises mailbox. Then, at the step 9, you could use Office 365 network upload service to import data to Exchange online mailbox.

In this way, you will could check whether PST files contain all emails correctly.

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