I think you are a bit naive. It doesn't matter if you delete your emails right after reading them. If they were on a web server they will be around for a LONG time. I personally think people who live in the cloud are destined for trouble in the end. Too much of your personal life, a heck of a lot more than you think, is stored on the web and accessible to people you don't even know and have never heard of.

I cannot understand why people insist that webmail like Gmail and web calendars like Google's are the way to go. You might as well just snail mail all your personal data to everyone in the world.