Currently if the mail is sent to a large group and if an administrator wants to take a report of "Read/Unread" status of that mail by every recipient, then there is no way to do that. Message tracking only allows you to track individual messages one by one and then it shows the Mailbox status as "Read" or "Unread". But for a large group, there is no way to do this in one go for all the recipients. So we can't take a report of Read/Unread status of the specific message.
So there is a feature request to add this feature so that an administrator can simply give Message ID or Subject and then system will generate a report showing "Read/Unread" status by every recipient of that mail.
This Enhancement Request is submitted for Domino V11 and V12.