Below are the links of few informative articles. These can help to resolve the issue.
http://tinyurl.com/lonryjy (You can monitor the complete system report including (body/message) even on daily basis.)
http://tinyurl.com/mlwgq6p (This link comes with an option to provide the static report of your sent email either the receiver has read your mail or still pending.)
In addition, you can also use automated exchange reporting tools like
this in case you are not able to do this with script.