My final year Computer Science project was based on data mining the enron email dataset. The raw Enron email dataset contains 517,424 real email log files organised into 3501 directories nested inside 150 employee mailbox folders.
I found this project extremely fun and had a really good time working on it. A future project idea of mine is to redevelop the Java application so it can plug into any dataset of email logs and expose the data. (Producing similar graphs, statistics). I may make this application open source and put it on my github.
The visualisation below displays how a specific email spreads throughout an organisation.