Have you looked into Analytics for Target also called A4T? This allows reporting of mbox and Target activity in Adobe Analytics. It is my preferred method for reporting all Target data.
Adobe Analytics as the Reporting Source for Adobe Target (A4T)
As far as the session goes, I am not sure that you will be able to fire an event based on session timeouts. Analytics sessions time out when a user has been inactive for 30 minutes, usually because their browser has been closed. Since the browser is closed, there is no mechanism that fires an event. Its not an event that occurs, it more that it expires.
What is it that you are trying to track and achieve with this reporting? If you could provide a little more detail, then maybe we could answer your question better.
Thanks