You must have Admin Level - Email/Print/Calendar access to view sent emails.
Click Org Tools > Email Center from the left navigation menu.
Click Display ALL or use the filters and click Search.
Click the "Subject" link (not the check box) to open the Message Track screen.
View the Subject Line, Message Body, and when the email was Sent.
Mails Probably NOT Opened shows all accounts that have not opened the email or our tracking code did not work in their email client. This often happens on mobile devices.
Unique Mails Opened shows those accounts that have opened this particular email.