1.  To see messages you have sent simply click on the Sent Messages icon on the top of the Message tab.  

sent messages

2.  A list of emails that you have sent will populate.  You will be able to see Who you sent the message to, the Title of the person who received the message, who the message was sent From and the Date/Time the message was sent. 

3.  You can click on the Message to read the content.