Curt Hopkins for The Daily Dot: “When a user “deletes” an email in the normal fashion, it becomes invisible to that user and is immediately a candidate to be overwritten. But until it is in fact overwritten, it exists. And it may persist longer on company servers. So, even if it is taken off your computer, it may still be available on the host’s server. Given that email-hosting companies are legally obliged to turn over user information to law enforcement and intelligence authorities with warrants—and these days even without them—the impossibility of being certain of a deletion means you must presume that any email you compose will be available remain accessible forever.”