Bitmessage is a newish service, created in the style of Bitcoin. It also uses public-key encryption, but when you send an email, it mixes it with all other emails being sent, which makes it pretty much impossible for anyone in the middle to figure out from where the email was sent. They also don’t have any information as to the receiver of the email, so each individual message contains the data from every other message that’s also going through Bitmessage. The receiver’s key, however, only retrieves the message that was intended for his or her inbox. Messages are also not archived; to keep from having a bazillion old emails floating around, being downloaded all the time, messages are deleted after two days. It’s completely decentralized, which might make it the best option for those who fear the government. Who is the government going to issue a request to? There’s nobody in charge!