Emailing or E-mailing is a method of direct marketing which uses electronic mail as a means of commercial communication to send messages to an audience. In its broadest sense, all emails sent to potential or existing customers could be considered emailing. However, the term is generally used to refer to: Sending emails with the purpose of enhancing the relationship of a merchant with its current or former customers to encourage customer loyalty and repeat business. Sending emails with the purpose of acquiring new customers or persuade existing customers to buy something now or in the future. Adding advertisements to email messages sent by other companies to their customers or users.