After Snowden's issue, several companies are coming forward to create secured E-mail services. Such one successful startup was Mailpile.
Now a new start up AirSpaceOne came with an idea of Secured E-mail client and Cloud storage based on personal pocket sized serve, which you can carry anywhere.
Read more about it on their Indiegogo campaign page - http://igg.me/at/aso/x/4669853
Read more about it on their Indiegogo campaign page - http://igg.me/at/aso/x/4669853