The 2 examples you've given aren't really the type of scams we deal with - the "loyalty points" is probably a phishing email ("Click here to claim your Tesco/WalMart/whatever points" and then enter your email and password) and the other is an area which may be a scam or may not (many people believe in mediums and happily pay for such services and the good feelings if gives them). But the principle of anyone being able to send the mails can easily be shown to your mother by looking in the Lottery Scams forum - there you'll find threads with Facebook and Google lottery scams, with many mails claiming to be from the companies (and sometimes even faked to look like they've been sent from facebook.com or google.com.
Please do not tell scammers that they are listed here - it will take them seconds to change their fake details and their new details will not be listed for any future victims to find.
