When you view the Server report found in the Inventory folder, the number of public folders is shown as 0 for some of the Public Folder servers
The Exchange Public Folders gathering is only running against specific servers and not against the entire Organization
Create a new Exchange Public Folders gathering to run against the Organization:
1. Open the MessageStats console and expand Exchange Organizations
2. Right click your Organization name and select Create Task
3. Enter a name for the new task. Click the drop down box, select Exchange Public Folders and click Next
4. Click OK if you get a Warning that there is a similar task
5. Click Next
6. Deselect Use Default Configuration
7. Select a schedule for how frequent you want the Public Folder gathering to run.
Note: The Public Folder gathering can take a long time to complete depending on how many Public Folders exist in the Organization. If the Public Folder gathering takes longer than 24 hours to complete or is causing other gatherings to take a long time to complete, it is advisable to schedule the Public Folder gathering to run once every weekend.
8. Click Next all the way throught the rest of the wizard and then click Finish to close the wizard