Starting soon you’ll be able to share tweets via email, directly from Twitter's website. A feature already present in the mobile app, you'll be able to send a tweet to anyone directly from your Twitter stream or the details of a particular tweet, regardless of whether or not the recipient is a Twitter user.
In addition to sending the tweet to a friend, you can also opt to add a personal comment to go along with it. The comment is sent along in the body of the email rather than on Twitter itself, allowing you to comment about a tweet without making those comments public.
The feature will slowly begin rolling out to Twitter users over the coming weeks, and will be available via a “More” button beside the Reply, Retweet and Favorite buttons currently below each tweet on the web.
In the Twitter-provided screenshot, “Email Tweet” is the only option that appears under the More button. Twitter creating a "More" drop-down menu, rather than simply adding an “Email” button, however, may mean that we’ll be able to do even more with tweets in the future.