The common root cause is that the account being used by LanGuard does not have enough access privileges to retrieve this information.
- Must be a member of the Exchange Organization Administrators domain group for the older versions of Microsoft Exchange or the Organization Management role group in the Exchange Server 2013 and more recent versions.
- Should have the Log on as a service right on Exchange.
Once you ensured that the required privileges are granted, let LanGUard gather the information from the Exchange server again. If the issue persists, contact GFI LanGuard Support.