View history of emails sent to a client from the client's profile

I am an instructor.  At the end of each lesson we have a conference reviewing the lesson's main objectives.  We send a "Take Away" document highlighting the point of the individual's / group lesson.  Each person receives a copy of this document.  When the client books another lesson a month down the road, I would like my coaches/myself to bring up the client's profile and review the last email/lesson sent to avoid duplicating the lesson or to follow thru with the correct successive lesson.