Error when you try to remove a mailbox database in Exchange Server 2019 or 2016

Article
03/31/2022
Applies to:

Exchange Server 2019, Exchange Server 2016

Original KB number: 3093175

Symptoms

Even if you've already moved or disabled all users, public folders, and arbitration mailboxes, you receive one of the following error messages when running the Remove-MailboxDatabase cmdlet. This message states there are still mailboxes left on a Microsoft Exchange Server database.

This mailbox database contains one or more mailboxes, mailbox plans, archive mailboxes, public folder mailboxes or arbitration mailboxes. To get a list of all mailboxes in this database, run the command Get-Mailbox -Database Database ID. To get a list of all mailbox plans in this database, run the command Get-MailboxPlan. To get a list of archive mailboxes in this database, run the command Get-Mailbox -Database Database ID -Archive. To get a list of all public folder mailboxes in this database, run the command Get-Mailbox -Database Database ID -PublicFolder. To get a list of all arbitration mailboxes in this database, run the command Get-Mailbox -Database Database ID -Arbitration.
To disable a non-arbitration mailbox so that you can delete the mailbox database, run the command Disable-Mailbox Mailbox ID. To disable an archive mailbox so you can delete the mailbox database, run the command Disable-Mailbox Mailbox ID -Archive. To disable a public folder mailbox so that you can delete the mailbox database, run the command Disable-Mailbox Mailbox ID -PublicFolder. Arbitration mailboxes should be moved to another server; to do this, run the command New-MoveRequest Parameters. If this is the last server in the organization, run the command Disable-Mailbox Mailbox ID -Arbitration -DisableLastArbitrationMailboxAllowed to disable the arbitration mailbox. Mailbox plans should be moved to another server; to do this, run the command Set-MailboxPlan MailboxPlan ID -Database Database ID.
+ CategoryInfo : InvalidOperation: (Database ID :DatabaseIdParameter) [Remove-MailboxDatabase], AssociatedUserMailboxExistException
+ FullyQualifiedErrorId : [Server= Server,RequestId= RequestId,TimeStamp= TimeStamp ] [FailureCategory=Cmdlet-AssociatedUserMailboxExistException] XXXXXXXX,Microsoft.Exchange.Management.SystemConfigurationTasks.RemoveMailboxDatabase
+ PSComputerName : Computer Name

This mailbox database contains one or more mailboxes, mailbox plans, archive mailboxes, public folder mailboxes arbitration mailboxes, or audit mailboxes. To get a list of all mailboxes in this database, run the command Get-Mailbox -Database <Database ID>. To get a list of all mailbox plans in this database, run the command Get-MailboxPlan. To get a list of archive mailboxes in this database, run the command Get-Mailbox -Database <Database ID> -Archive. To get a list of all public folder mailboxes in this database, run the command Get-Mailbox -Database <Database ID> -PublicFolder. To get a list of all arbitration mailboxes in this database, run the command Get-Mailbox -Database <Database ID> -Arbitration. To get a list of all Audit mailboxes in this database, run the command Get-Mailbox -Database <Database ID> -AuditLog. To disable a non-arbitration mailbox so that you can delete the mailbox database, run the command Disable-Mailbox <Mailbox ID>. To disable an archive mailbox so you can delete the mailbox database, run the command Disable-Mailbox <Mailbox ID> -Archive. To disable a public folder mailbox so that you can delete the mailbox database, run the command Disable-Mailbox <Mailbox ID> -PublicFolder. Audit mailboxes should be moved to another server; to do this, run the command New-MoveRequest <parameters>. If this is the last server in the organization, run the command Get-Mailbox -AuditLog | Disable-Mailbox. Arbitration mailboxes should be moved to another server; to do this, run the command New-MoveRequest <parameters>. If this is the last server in the organization, run the command Disable-Mailbox <Mailbox ID> -Arbitration -DisableLastArbitrationMailboxAllowed to disable the arbitration mailbox. Mailbox plans should be moved to another server; to do this, run the command Set-MailboxPlan <MailboxPlan ID> -Database

Cause

This issue occurs because Exchange Server 2016 and 2019 introduces an AuditLog mailbox. This mailbox may be still present and blocking removal of the database.

Resolution

To fix this issue, use the Get-Mailbox cmdlet together with the -AuditLog parameter to determine whether the AuditLog mailbox is still present. To do this, run the following cmdlet in the Exchange Management Shell:

Get-Mailbox -AuditLog -Database <DatabaseName>

If the AuditLog mailbox is present, use one of the following methods:

If it isn't the last mailbox server and database in the organization, move the mailbox to a different database by running the following cmdlet in the Exchange Management Shell:
```
Get-Mailbox -AuditLog -Database <SourceDatabaseName> | New-MoveRequest -TargetDatabase <TargetDatabaseName>
```
If it's the last mailbox server and database in the organization, you can safely remove it by running the following cmdlet in the Exchange Management Shell:
```
Remove-Mailbox -AuditLog
```