The emails notify you about files that are about to be unshared.
The frequency of the emails depends on how your organization's administrator has configured Tricent. By default, you receive a notification seven, three, and the day before the unsharing. Once completed, you get an email listing the unshared files.
You don't have to do anything if you are okay with the files being unshared. Tricent will just go ahead and unshare the files.
Read more about the process right here.