How to produce a report based off OCS/Lync users last logon date or if they have not logged on in x amount of days.
1. Open MessageStats Web Reports
2. Expand Report Packs OCS/Lync Server | Organizational Summaries | User Activity | Summary
3. You can run this report by "Between" and choose your timeframe and then click Apply Filters
4. After right-click the blue pane at the top and click Insert Field and select "Last logon Date"
5. Next, right-click the Last Logon Date field and click "Sort Ascending"
The Users that show up with a Last Logon Date being Blank in this report are the users that have not logged in within the timeframe you specified. Your best bet after this point is to Export to Excel and apply your own filters to get a better Idea of those users who have logged in or have not logged into within the date you choose