Facebook introduced its email service, @facebook.com, back in November of 2010. Since then, it’s been slow catching on as most users avoided using it in favor of their own email addresses. Now, the social giant has replaced all firstname.lastname@example.org email addresses with their proprietary email, though Facebook is routing emails that come to those swapped addresses over to the original registered user’s address.
This is another instance of Facebook changing something that affects every user and doing so without much public announcement. This change was announced through a quiet statement back in 2010:
As we announced back in April, we’ve been updating addresses on Facebook to make them consistent across our site. In addition to everyone receiving an address, we’re also rolling out a new setting that gives people the choice to decide which addresses they want to show on their timelines. Ever since the launch of timeline, people have had the ability to control what posts they want to show or hide on their own timelines, and today we’re extending that to other information they post, starting with the Facebook address.
Luckily, users can switch back. If you don’t want @facebook.com as your display email address, you can fix that by simply going to your user settings and changing it back.
Click on your name (usually at the top-right), then “Update Info” and then edit your contact settings. Your old address is likely shown as “hidden” with the new @facebook.com address displayed instead. Either remove the @facebook.com address or make your other email the active email.