Defeat spam with Postgrey by greylisting and whitelisting incoming mail

Hail Mail

Article from Issue 142/2012

Vendors continue to develop new defenses against spam, one of the Internet’s most notorious pests. In this article, we integrate Postgrey with the Postfix mail server for a greylisting and whitelisting solution.

Spammers flood mail servers with unwanted email every second of every day just as fast as their software allows. Ham (solicited email, as opposed to unsolicited email), on the other hand, is conservatively estimated to be only around 5 to 10 percent of the email on the Internet as a whole (depending on which study you believe). Spammers continue to send unsolicited email because there’s something in it for them – namely, profit gleaned from recipients who unwittingly click on links in email messages and then buy pharmaceutical products and the like. It’s been said that if no one clicked, no spam would be left.

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