To the surprise of no one, Facebook has announced that it will no longer forward your facebook.com emails to your actual email, thereby giving you yet another reason to open up that app or visit their page so they may collect that sweet sweet data about you and sell it to advertisers. After 1 May 2016, you will no longer be able to receive email sent to your facebook.com account as a forward to your real email account.
If you're squinting your eyes now, wondering what "facebook email" is, do you remember that email address @facebook.com that Facebook set up for you in 2010? Yeah? Well in 2012 they set it as a default in your facebook profile, so anyone viewing that, looking to find your email, found your facebook email instead. So now all your featherhead friends who couldn't remember your email and went to facebook to find it, didn't.
You could still manage to keep in touch with those silly friends of your who use facebook, by setting that email up to forward to your real email.
And now, they're breaking that. Of course they are. I suggest as appropriate response is to delete your facebook account. But be careful, if you use facebook login anywhere you'll break that.