Yahoo! will start giving consumers the option of end-to-end encryption in its Mail service by next year. Chief Information Security Officer Alex Stamos announced the move at Black Hat 2014 hacking conference. The move to encrypted mail will bring Yahoo! in the list of the most secure technology companies in mail services among web giants, Google and Microsoft that protect their customers in the post-Snowden era of security. Only senders and recipients will be able to read the messages exchanged between its users.
Source: https://thehackernews.com/2014/08/end-to-end-encryption-for-yahoo-mail.html