Issue: Unable to find mailbox
Resolution:
Since this was a returning user and there was no hold (LitigationHoldEnabled: False) on the user, there was a possibility that the mailbox might be deleted already. We confirmed that by running Get-Mailbox <User> -SoftDeletedMailbox and Get-Mailbox <User> -InactiveMailboxOnly, no object was found using those commands.
Get-Mailbox [email protected] -SoftDeletedMailbox
Get-Mailbox [email protected] -InactiveMailboxOnly
Because there was an ExchangeGUID set On-Prem, Exchange Online wouldn’t provision a new mailbox and was trying to re-attach a mailbox that didn’t exist. We removed the old ExchangeGUID On-Prem (dd014f80-fa99-4455-85a0-1558b7bf614d) as well as checking these attributes to ensure Exchange Online provision a mailbox.
- Confirmed msExchRecipientDisplayType: -2147483642 (MailUser (RemoteUserMailbox))
- Confirmed msExchRecipientTypeDetails: 2147483648 (RemoteUserMailbox)
- Changed msExchRemoteRecipientType: 6 (ProvisionArchive, Migrated) to 3 (ProvisionMailbox, ProvisionArchive)
We waited for the AD Sync to replicate the attributes to EXO, and mailbox was provisioned. We also tried to copy the data from the old mailbox to the new mailbox by using the old ExchangeGUID, just in case.
- New-MailboxRestoreRequest -SourceMailbox “dd014f80-fa99-4455-85a0-1558b7bf614d” -TargetMailbox “8ab4c072-da63-4b39-840b-f4baee8ab167” -AllowLegacyDNMismatch
The command returned an error that there was no object with the old ExchangeGUID. We then confirmed that the mailbox was indeed provisioned and working as intended.