The Registry Key "ExchangeWebserviceURL" is not present or not populated correctly within the SMSMSE directory
The status of manual scan in the console is FAILED or in the application event log you may see an event id 396 with text similar to the following:
The scan Manual could not be completed as Microsoft Exchange's Client Access Server is not reachable.
Either permissions prevented the population of the registry value or Autodiscover failed to return the correct data for the Exchange web URL during installation. Manual scans can not complete because Exchange.asmx can not be located.