Not receiving email notifications

I really would appreciate some help please. I've always ever since starting on FB, received email notifications for every post by my friends but for the last couple of days I don't receive them all - all my friends on FB have the same settings - that is I've never changed them so am confused about what is happening now . I've gone through the usual settings/notifications etc. but really can't understand most of it and that's why I've never changed anything. I've contacted FB via email but just got a thank you email advising emails help blah blah.....it was noting saying FB would look into my problem. I've been though my email account and can send/receive others without a problem. Can someone help me please?

Thanks
Nessy