It’s tough to get people to switch from one email service to another — getting a new email address might be even more annoying than having to switch phone numbers. So, as proud as the Gmail development team is of their product’s features, it’s to this point been no guarantee that anyone will be convinced to change over because of them. Now, they’re taking another approach — with a new feature called Gmailify, you can now get Gmail features on a Yahoo and Hotmail/Outlook accounts that have been linked to your Gmail account.
Last year, Gmail made it possible to link those other email addresses to a Gmail account in the Gmail app for Android. Gmailify builds on that by allowing you to use Google’s spam filters, organization tools, and Google Now cards on those addresses as if they were actual Gmail addresses.
It’s pretty simple to activate, too — once those other addresses have been linked, just turn Gmailify on in settings and you’re done (if they aren’t already linked, linking them will automatically take you through activating Gmailify). It’s the perfect feature for anyone who likes Gmail but doesn’t like the prospect of abandoning an old email address. After all, those old email addresses probably have old emails you’d like to be able to search through easily, to say nothing of the chore of having to send out your new email address to your contacts.
Via Gmail Blog