The ROM developer has announced that it has begun rolling out the (CM12S) Cyanogen OS 12 update for the One.
The update also adds in the new email app, Cyanogen Email, which is powered by Boxer. It is a replacement for the Gmail app. It offers all the premium features of Boxer for free, including Exchange Support, Multiple Accounts, Canned responses, customization of the LED color for new email notifications, Swipe to dismiss/delete/archive and more.
The Cyanogen OS 12 update for Yu Yureka is coming soon.