The inbox message has a yellow/tan box below it that says "To reply to this message, follow the link below." Then there are a lot of numbers and letters which have no meaning to me.
The sender should be shown at the top of the message. If this is missing then it is probably a fake notification email which is intended to look like it came from Facebook; they probably want you to click on the link and maybe enter your Facebook login and password on their fake site. Obviously you should not do that.