Have you ever received e-mails with the contents saying that you have won a prize from a company? Or an e-mail that tells you that someone has inherited a big sum of money for you?
This kind of e-mail or unwanted e-mail especially those which tell a BIG lie to you is called SPAM.
Well, if you receive this kind of e-mail you should mark it as spam by pressing the Report Spam button, then delete it. Look at the picture of gmail inbox with the Report Spam button.
If you don't mark it, maybe you will receive this e-mail again in a very short time. To know more about this you can copy the name of the sender and paste it in Search Engine. You will then see links about the spammer.