Most of the email messages being sent on the Internet are SPAM. Businesses found the power of email marketing and started using it by sending millions of emails to gain new customers and increase revenue. There is nothing wrong with email marketing as long as the emails are sent to subscribers who provided their email addresses themselves and agreed to receive those kind of messages. What happens in reality is that companies use bots and web spy machines which would crawl web sites to find emails. Then they save them into a database and start sending them offers for different kind of products. There are many people who are doing it without realizing that is illegal. They don’t know what SPAM is. Basically, that is sending of unsolicited email messages in an attempt to advertise a product. You can learn more about it at https://en.wikipedia.org/wiki/Spamming.