Remove last Exchange server in the Organization

Before removing the last Exchange server in the organization we must make sure that all the Exchange databases are removed. We cannot have any mailboxes still active, as they are tied to Active Directory and deleting the server without gracefully delete or disconnect mailboxes would leave the AD with residues of the server and wrong properties all over the place.

1. Check what databases are left and to be removed

Check databases hosted on the last mailbox server

PS C:\> Get-MailboxDatabase -Server MAIL

Name                           Server          Recovery        ReplicationType
----                           ------          --------        ---------------
DB01                           MAIL            False           None


PS C:\>

Disable Offline Address Book to remove the last arbitration mailbox from the system

PS C:\> Get-OfflineAddressBook | Remove-OfflineAddressBook

Remove mailboxes (only non-arbitration mailboxes!):

PS C:\> Get-Mailbox -Database DB01 | Disable-Mailbox
PS C:\> Get-Mailbox -Database DB01 -Archive | Disable-Mailbox -Archive
PS C:\> Get-Mailbox -Database DB01 -PublicFolder | Disable-Mailbox -PublicFolder
PS C:\> Get-Mailbox -Database DB01 -AuditLog | Disable-Mailbox
PS C:\> Get-Mailbox -Database DB01 -Arbitration | Disable-Mailbox -Arbitration -DisableLastArbitrationMailboxAllowed

When done, remove the last database:

PS C:\> Remove-MailboxDatabase DB01

Demote Mailbox Server

Use appwiz.cpl to locate Exchange in the software deployment list and proceed with the uninstallation.