Facebook has decided to shut down its Facebook.com email service where you could receive emails into your Facebook inbox. Apparently not many users were actually using it.
You have the option of disabling the service in the meantime and, if you don’t, emails sent to your Facebook.com email address will be forwarded to your primary email address. As The Verge pointed out, there is, however, a problem with this:
Today’s update brings another odd and unfortunate side effect for Facebook: you can now reach someone’s primary email inbox by emailing their @facebook.com email address. These email addresses are by default only accessible to friends, but you can easily figure out somebody’s @facebook.com email address by finding their profile page’s URL and pasting it before the @ symbol. Fortunately, Facebook lets you turn off forwarding altogether, effectively destroying its email service once and for all.