Privacy Oriented Email Service

During my research of preventative measures, I came across a method of how to increase online privacy related to emailing.  This is for people or companies who are very worried about privacy and emails, which is a growing problem nowadays.  There are safe and trustworthy email services out there that protect your emails and keep them safe, secure, and private.  I came across an example of one quite well renowned email service call Hushmail.  Hushmail encodes each message with an encryption.  This makes the message unreadable to anyone but the sender and its recipients.  The message is encrypted before it is even sent, and is restored back to its original form once it is received by the recipient.  All the recipient and the sender have to have in common and remember is a secret personal passphrase.  This allows the sender to lock the email, and the recipient to unlock the message.  Although this is not a new service or technology, I had never heard of it, but I do think it is quite useful and has a lot of potential.  This could be vital for a lot of organizations, and even the government.  Here is the Hushmail website. http://www.hushmail.com/