For projects created after March 22, 2018, you can now find the last email in a thread with one click! In the QC Tag filter in the carousel, there is a "Last Email" option you can select.
An email tagged with the "Last Email" QC Tag is the last message of an email thread, or is a message without a thread. When part of a thread, this tag indicates the end of a particular thread and not the inclusiveness of the thread's contents within this email. Please note that we do have a version 2 of this feature in the works to compare the text within all the threads.
Last Email makes it fast and easy to cull your documents for review. When combined with other search filters, the Last Email filter can be very powerful. For example, using Power Search you can run a search for all emails that have threads and tagged with Last Email:
Once opened, you can scan through the threads in the document info panel. You will notice that you can now see the timestamp of every email in the thread: