A large number of legitimate organizations send out enormous amounts of email to happy subscribers every day. However, it can be difficult to provide information on how to better accomplish this task without also providing information that is valuable to spammers, people who send out vast amounts of unsolicited email, typically advertising shady or illegal products. One key difference between the legitimate bulk-email houses and spammers is that the bad guys don't care if some of their messages get lost along the way. In contrast, those organizations providing a service that people actually want are more likely to make sure that their information reaches its intended destination. Spammers tend to "fire and forget" email messages, whereas large, beneficial mailing lists want to fsync() messages as they're queued to ensure that they don't vanish. Therefore, by focusing on "safe" outbound emailing, we can provide information of value to legitimate mass-mailing houses without fear that the spammers will benefit significantly from it. In general, the problem of sending out mass email can be divided into three categories:
Each has its own characteristics and will be dealt with separately in this chapter. |