Paper on E-mail security and privacy

During my exchange study I wrote a paper on E-mail security and its privacy issues. It discusses the way the e-mail protocols are used, where the threats and vulnerabilities lie and how to increase your security risk. E-mail has become a way of communincating which we adopted into are lifes. But there are still several flaws which the common user does not know of and several of them can easily be avoided. Any comments on the paper are welcome.