On Monday, Facebook rolled out a new change where everybody’s published email address under contacts, was changed to a newly assigned one based on the @facebook.com format. What this means for Facebookers is that anyone emailing them via their Facebook account would see their mail end up in FB messages, not the usual email inbox.
Facebook maintains it is giving the user the choice of email but as The Guardian blog puts it,
We shall gloss over the question of whether a “choice” really exists if a user is not aware of it.
Go to your Facebook profile, and click on the “About” button, which is somewhere under your profile picture. Where you see “contact info”, click on “edit”. Next to your real email address, click on the little box that says “hidden from timeline”. Change it to ‘Shown on timeline’. Now click on the box next to the impostor Facebook email address. Change it to “hidden from timeline”. Click save. Exit Facebook.