This issue is quite common and in most instances is easily resolved with the steps below.

1. Open ScanMail Web Console .
2. Go to Administration->Server Groups menu then click Refresh button.

3. Check whether the Three groups contain all of the Exchange Servers if yes process to Step 4.
4. Try to do Log Query again to check if issue still persist.


If the issue persists it will be necessary to capture a debug log using the CDT tool while preforming the steps above. These can then be provided to Trend Micro support in a new support case. Details on using the CDT tool can be found in the link below.
https://success.trendmicro.com/solution/KA-0011430