ManageEngine Exchange Reporter Plus license is based on the number of mailboxes. You need to buy a license corresponding to the number of mailboxes in your Exchange Organization. However, if you require data to be collected from specific mailboxes present across the Exchange servers, you can selectively manage those mailboxes using the manage/unmanage option in the product. Data is gathered for reporting only from the mailboxes that are managed.
When you download and install the product, the product starts in a trial mode. This is fully functional for 60 days. In the trial mode, data is gathered for reporting from your entire Exchange Organization.
After the 60 days, the trial license expires and the software stops to fetch fresh data from the Exchange Organization. However, reports on the previously fetched data can be viewed and used.
You can anytime convert to the commercial version from the trial mode by applying a valid ManageEngine Exchange Reporter Plus license. This license can be applied during the trial period or even if the trial period has expired.