Email marketing is good for the business and it is a powerful marketing tool that helps an organization to scale new heights. In short a commercial message is sent to a group of people via email.
In a broader context every email that is sent to a prospective or a current customer is part of email marketing. The purpose of the email is to build relationships and to ensure that the customers have a sense of brand loyalty. On the other hand traditional mail is triggered as a reaction of a customer to a particular aspect of the company.