With little time and effort, a multitude of people can be reached via the internet. At the same time, companies can distribute advertisements for their products to a great mass of consumers in order to increase their sales. Since pressure of time and costs have come to be the norm, many companies give no thought to whether the addresse has given their consent to receive advertisements or not, for not every internet user wants to be bombarded with hundreds of e-mails every day. To prevent such unacceptable harassment, the law has arranged for tight guidelines. The lecture aims to give an overview of points to keep in mind when sending advertisements via e-mail.