At this time there is a lawsuit in the United States Federal Court System, Northern District of California San Jose Division Case Number 13-MD-02430-LHK “IN RE: GOOGLE INC. GMAIL ITIGATION”
This lawsuit was originally brought by nine individuals, some of whom were holders of Gmail accounts and some of whom were not, but who had received and or had sent email from or to Gmail account holders. In the suit they put forth the claim that Google had in fact violated several laws, most notable being Federal anti-wiretapping statute. (Maybe they were just piggy backing on top of the NSA). The lawsuit claims that Google was in fact doing this systematically. (Shock, computer were designed to be systematic.) The suit claims that Google was doing this to profit. (What a freaking surprise.)
Just in case your parents never told you or for that matter your lawyer there are very few places that you can go, very few modes of communications, or very few actions that you do in which you should realistically have an expectation of privacy. E-mail is one of those modes of communications where if you are smart you will not have an expectation of privacy. Your e-mail provider knows the who, what, and when of your e-mail. The recipients of your email, their provider knows the who, what, and when of their e-mail. It is not only a wire tap, it is two wire taps, quite possibly three if you include the NSA since in all reality it is quite possible that they have a backdoor into the various large client mail servers. (They might be the few who can actually see end to end on your e-mail if they are so inclined.) Privacy, as far as e-mail is concern it fairy dust.
You will never get away from the who or the when, that is built into the system. But the what, that is a different matter. You have the ability to encode/encrypt you message. If you are not encrypting your message then shame on you. There are several encrypting packages that can be used, pick one, but know that it is not entirely secure. (As the title of the program says Pretty Good Privacy.) For the very paranoid among us we can use some type of off line one time cypher pad to encrypt our message, then encrypt the message again using a less secure method, send the message to your special friend, with the understanding that your ISP, and their ISP, and in all probability the NSA, at the very least have the who, and when, and possible the what of your message traffic. Realize at some point the NSA will or might realize that you have friends and that you also have special friend.
At the very least you need to have several e-mail accounts with various ISP. I have a several. They all have their particular uses. Mail, Junk Mail, Really Junk Mail, and finally Crap Mail, you get the picture. For God Sakes blow the cookie away, flush those buffers, randomly just quite and restart your browser. Hell for that matter randomly shut down your computer. Defrag and Compact your hard drives, zero out the free space on the drive.
Take to heart the words of the theme song for Monk, by Randy Newman, "It's a Jungle Out There" , in particular the passage "You better pay attention Or this world we love so much might just kill you"