which is the most common use of opt-in e-mail marketing
Email marketing A common example of permission marketing is a newsletter sent to an advertising firm's customers. Such newsletters inform customers of upcoming events or promotions, or new products.[14] In this type of advertising, a company that wants to send a newsletter to their customers may ask them at the point of purchase if they would like to receive the newsletter.
Email address Earlier forms of email addresses on other networks than the Internet included other notations, such as that required by X.400, and the UUCP bang path notation, in which the address was given in the form of a sequence of computers through which the message should be relayed. This was widely used for several years, but was superseded by the Internet standards promulgated by the Internet Engineering Task Force (IETF).