CmdID / PowerShell / Cmdlets / Enable
Enable-UMServer
Use the Enable-UMServer cmdlet to set the status of a Unified Messaging (UM) server to enabled. Exchange PowerShell reference
From the Exchange PowerShell reference 4 parameters Its page in the reference
Parameters
-IdentityThe Identity parameter specifies the identifier for the Unified Messaging server being enabled.-Confirm, -cfThe Confirm switch specifies whether to show or hide the confirmation prompt.-DomainControllerThe DomainController parameter specifies the domain controller that's used by this cmdlet to read data from or write data to Active Directory.-WhatIf, -wiThe WhatIf switch shows what the command does without making any changes.