Restore a deleted Exchange mailbox before the 30 day retention ends. Find the mailbox with Get-MailboxStatistics and its disconnect reason. Reconnect a disabled mailbox with Connect-Mailbox. Restore into another mailbox with New-MailboxRestoreRequest. Microsoft documents Exchange 2016 and newer on these pages. Steps follow the official pages and were not tested here.
Deleted mailboxes do not vanish at once. Exchange retains them in the mailbox database until the retention period ends.
Facts follow Microsoft Learn Disconnected Mailboxes in Exchange Server. Microsoft lists Exchange Server 2016, 2019 and Subscription Edition. Our old post named Exchange 2010, which these pages do not list.
What is a Disconnected Mailbox?
Disconnected mailboxes sit in the mailbox database without an Active Directory user account. Microsoft names two types.
- Disabled. Mailbox was disabled or deleted in the EAC or with Disable-Mailbox or Remove-Mailbox. Retention is 30 days by default.
- Soft-deleted. Mailbox moved to another database and the source copy remains in case the move fails. Retention is 30 days or until Remove-StoreMailbox purges it.
How to Find a Deleted Mailbox?
Query every database with Get-MailboxStatistics and filter on the disconnect reason. Use Disabled for disabled mailboxes and SoftDeleted for soft-deleted ones.
Microsoft states that the command returns nothing when the mailbox was purged.
How to Restore a Deleted Mailbox in Exchange?
Microsoft lists four options before the purge.
- Reconnect the mailbox to the same user account.
- Connect it to a different user account that has no mailbox.
- Restore it into an existing mailbox with New-MailboxRestoreRequest. This merges the content.
- Delete it permanently.
In the EAC select Recipients, Mailboxes and Connect a mailbox. Microsoft links a separate article for the full steps.
When does Exchange Purge a Mailbox?
Exchange purges disconnected mailboxes after the retention period. You can purge early with Remove-StoreMailbox. According to Microsoft, Remove-Mailbox with -Permanent deletes the mailbox at once and a purged mailbox cannot be recovered.
What does Microsoft Not Say?
- Steps for Exchange 2010 or 2013 on these pages.
- Recovery of a mailbox from a backup file.
- Recovery after the retention period ends.
- Mailbox export to PST on these pages.
Related reading: how to recover deleted items from the Exchange dumpster and how to restore an Office 365 mailbox from backup.
Frequently Asked Questions
How Long does Exchange Retain a Deleted Mailbox?
Microsoft states that the default retention is 30 days. Retention is set per mailbox database.
How do I Find a Disconnected Mailbox?
Use Get-MailboxStatistics on every database and filter on the disconnect reason Disabled or SoftDeleted.
How do I Reconnect a Disabled Mailbox?
Select Connect a mailbox in the EAC or use the Connect-Mailbox cmdlet before the retention period ends.
Can I Restore a Purged Mailbox?
No. Microsoft states that data loss is permanent once a mailbox is purged.
Do These Pages Cover Exchange 2010?
No. Microsoft lists Exchange Server 2016, 2019 and Subscription Edition.
Key Takeaways
- Exchange retains disabled and deleted mailboxes for 30 days by default.
- Find them with Get-MailboxStatistics and the disconnect reason.
- Reconnect with Connect-Mailbox or restore with New-MailboxRestoreRequest.
- Purged mailboxes cannot be recovered.
- Microsoft lists Exchange 2016 and newer on these pages.
Sources and References
Facts follow Microsoft Learn.
- Disconnected Mailboxes in Exchange Server (Microsoft Learn) learn.microsoft.com