Set a user to have impersonation rights in Exchange 2007
(Add these commands with Exchange Management Shell PowerShell)
This user will be allowed to search users inbox for new voicemails

1) Add-ADPermission -Identity (get-exchangeserver -Identity MyMailServer).DistinguishedName -User (Get-User -Identity MyUserName | select-object).identity -extendedRight ms-Exch-EPI-Impersonation

2) Get-MailboxDatabase | Add-ADPermission -User MyUserName -ExtendedRights ms-exch-EPI-May-Impersonate


-Replace MyUserName and MyMailServer with your information.
