Early last year, Google started offering users of other email providers access to certain Gmail features. Finally christened ‘Gmailify’, the service has evolved to offer significantly more functionality.
Major features like spam protection, inbox organisation (with labels) plus Google Now cards are available for Yahoo! Mail and Hotmail/Outlook accounts to peruse.
To enable the service a user needs to login to the Android Gmail app, sign in and enable Gmailify. Since it isn’t permanent you can link/unlink at any time.
Google is planning to enable the feature on iOS as well as add compatibility with other email providers in the coming months.
[Via Google Blog]