What kind of research can be done with an email data set? I found a data set called Enron Email Dataset. It is possibly the only substantial collection of "real" email that is public. I found some prior analysis of this work:


A paper describing the Enron data was presented at the 2004 CEAS conference.
Some experiments associated with this data are described on Ron Bekkerman's home page
Parakweet has released an open source set of Enron sentence data, labeled for speech acts.
Work at the University of Pennsylvania includes a query dataset for email search as well as a tool for generating spelling errors based on the Enron corpus. 


I'm looking for some interesting current trend topics to work with.please give me some suggestions.
The following are some research that can done on e-mail dataset:


linguistic analysis to abbreviate an email message
Categorize e-mail as spam/ham using machine learning techniques.
identifying concepts expressed in a collection of email messages, and
organizing them into an ontology or taxonomy for browsing