How does MessageStats determine which Distribution Lists appear in the Distribution Groups | Inactive Groups | By Distribution List report?
The Distribution Lists that appear in the Distribution Lists | Inactive Lists | By Distribution List report are any Distribution Lists that have not seen activity in the Exchange Tracking Logs during the reporting period you specify when you generate the report.
For example: If you specify the Date filter as last 30 days, the distribution lists that appear in the report are all the distribution lists that have not appeared in the Exchange Tracking Logs in the past 30 days
