Microsoft Exchange Server 2013 Decommission

Case : Uninstallation of an Exchange Server 2013 after Exchange Online Migration, non hybrid environment.

Mailbox cleaning

Get-User | Disable-Mailbox
Get-Mailbox -Arbitration | Disable-Mailbox -Arbitration -DisableLastArbitrationMailboxAllowed
Get-Mailbox -Monitoring | Disable-Mailbox

Removing restore mailbox

Get-Mailbox | Get-MailboxStatistics | Where {$_.DisconnectReason -eq “Disabled” } |foreach {Remove-StoreMailbox -Database $_.database -Identity $_.mailboxguid -MailboxState Disabled}
Get-Mailbox | Get-MailboxStatistics | where {$_.DisconnectReason -eq “SoftDeleted”} |foreach {Remove-StoreMailbox -Database $_.database -Identity $_.mailboxguid -MailboxState SoftDeleted}

Removing Offline Address book

Get-OfflineAddressBook | Remove-OfflineAddressBook

Verify nothing’s left

Get-Mailbox
Get-Mailbox -Arbitration
Get-Mailbox -Monitoring

Remove Database

Get-MailboxDatabase | Remove-MailboxDatabase

Remove partner application

Get-PartnerApplication| Remove-PartnerApplication

Run Exchange uninstallation

Setup /Mode:Uninstall /iacceptexchangeserverlicenseterms