OBRM application uses the remote connection mechanism via PowerShell to Exchange server.
As stated in Microsoft forum: <<Remote Power Shell is the feature added in E2K10. So it will not work in Exchange 2007.>>
https://social.technet.microsoft.com/Forums/exchange/en-US/0bd63e9a-70a1-45b0-8b98-15753384ab33/powershell-remoting-exchange-server-2007?forum=exchangesvradminlegacy but there is a possibility to enable remoting by means of upgrading WinRM and PowerShell versions on the server.
Follow the instructions from the following Microsoft article: