E-mail marketing has always been an effective method of promotion, until it is not considered as spam. It is essential because if the e-mail marketing is seen as spam, it is not read by the recipient and ultimately cannot reach the receiver, as provided by ISP's anti-spam filter. Therefore it is important for entrepreneurs to work hard to ensure that the use of e-mail marketing is not spam by both of the recipient or the recipient of the Internet service provider. This article will journey as along the topics of e-mail marketing, and in particular how companies can protect their e-mail is not regarded as spam.