Facebook forces @facebook.com e-mail addresses to all users
Facebook now changed the displayed default email address of all users to its own @facebook.com email addresses without any warning.
may reduce the email spam.
mails do not land in the inbox of your connected email account.
visit your Facebook’s profile page.
click on the update info button.
locate Contact Info module and click on the edit button.
click the button and select hidden from timeline.
to show original email address select the shown on timeline option.
click on the save button at the bottom of the menu to save the changes.