Applies to: Exchange Server SE / 2019 / 2016
After moving a mailbox to another mailbox database, you may still see the old mailbox on the source database with a SoftDeleted disconnect reason. This is expected behavior in Exchange Server, including Exchange Server Subscription Edition, Exchange Server 2019, and Exchange Server 2016.
The mailbox on the source database is not another active copy of the user mailbox. Exchange keeps the source mailbox temporarily so that its data can still be used for recovery if something goes wrong after the move.
In This Article
- 1. Why This Happens
- 2. Check Soft-Deleted Mailboxes
- 3. Check Mailbox Retention
- 4. Should You Delete It?
- 5. Permanently Purge a Soft-Deleted Mailbox
- 6. Key Takeaways
1. Why This Happens
When a mailbox move between Exchange mailbox databases completes, Exchange does not immediately remove the mailbox data from the source database. Instead, the source mailbox is changed to the SoftDeleted state.
This gives Exchange a recovery window. If the mailbox on the destination database has a problem after the move, the data in the soft-deleted source mailbox can still be used in a mailbox restore operation.
This is different from a mailbox with a Disabled disconnect reason. Both are disconnected mailboxes, but a soft-deleted mailbox is normally created as part of a mailbox move.
2. Check Soft-Deleted Mailboxes
To check one mailbox database, run:
Get-MailboxStatistics -Database "DB01" | Where-Object {$_.DisconnectReason -eq "SoftDeleted"} | Format-Table DisplayName,MailboxGuid,Database,DisconnectDateTo check all mailbox databases in the organization:
Get-MailboxDatabase | ForEach-Object {
Get-MailboxStatistics -Database $_.DistinguishedName
} | Where-Object {$_.DisconnectReason -eq "SoftDeleted"} | Format-Table DisplayName,MailboxGuid,Database,DisconnectDateThe important value here is DisconnectReason. If it is SoftDeleted and the active mailbox is healthy on the destination database, seeing the source copy is normally expected.
3. Check Mailbox Retention
Soft-deleted mailboxes are retained according to the deleted mailbox retention setting on the mailbox database. The default retention period is 30 days unless it has been changed.
Get-MailboxDatabase "DB01" | Format-List Name,MailboxRetentionIf there is no reason to remove the mailbox immediately, Exchange can simply keep it until the retention period expires and purge it automatically.
4. Should You Delete It?
In most cases, there is no need to manually purge a soft-deleted mailbox immediately after a successful move. Keeping it during the retention period gives you an additional recovery option.
Manual cleanup can make sense when you have verified the destination mailbox and need to reclaim database space, remove a mailbox database, or clean up old soft-deleted mailboxes for a specific operational reason.
Before deleting anything, confirm that you are looking at the source copy and that the active mailbox on the destination database is healthy.
5. Permanently Purge a Soft-Deleted Mailbox
Remove-StoreMailbox permanently deletes the mailbox and its message content from the mailbox database. This operation cannot be undone from that mailbox copy.
First, identify the mailbox GUID from Get-MailboxStatistics. You can then test the command with -WhatIf:
Remove-StoreMailbox -Database "DB01" -Identity "MAILBOX-GUID" -MailboxState SoftDeleted -WhatIfAfter you have verified the database and mailbox GUID, run the command without -WhatIf:
Remove-StoreMailbox -Database "DB01" -Identity "MAILBOX-GUID" -MailboxState SoftDeletedI prefer targeting the specific mailbox rather than immediately running a bulk purge command. It makes the cleanup easier to verify and reduces the chance of removing a mailbox copy you still need.
6. Key Takeaways
- A mailbox move can leave the source mailbox in a SoftDeleted state. This is expected behavior.
- The soft-deleted source mailbox remains available until the mailbox retention period expires or it is manually purged.
- Do not purge it just because it appears as disconnected. Verify the destination mailbox first.
- Remove-StoreMailbox permanently deletes the selected mailbox copy, so use it only when cleanup is intentional.
References
Cloud and infrastructure professional with nearly two decades of experience in enterprise IT environments, spanning public cloud, private cloud, and hybrid architectures.