Explanation:
Though spams are not going to be reliable, some state disallows spams.
Let us understand the term "spam". Any e-mail which is not send to the person without any need, or any mail sent to bulk users without requesting is termed as spam.
If the customer wish to receive messages about product promotions then the company can send it. If a company wants to send product promotion to many then this will fall under spam. But still the law preempts the email with some exceptions.