Defeat spam with Postgrey by greylisting and whitelisting incoming mail

Hail Mail

Article from Issue 142/2012
Author(s):

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.

Buy this article as PDF

Express-Checkout as PDF
Price $2.95
(incl. VAT)

Buy Linux Magazine

SINGLE ISSUES
Print Issues
Digital Issues
 
SUBSCRIPTIONS
Print Subs
Digisubs
 
TABLET & SMARTPHONE APPS
Get it on Google Play

US / Canada

Get it on Google Play

UK / Australia

Related content

  • IndiMail 1.6 Includes Greylisting and BATV

    IndiMail, an email solution made of open source components, now includes greylisting spam filtering in version 1.6.

    more »
  • Greylite: Greylisting for Qmail

    Version 1.1 of Greylite, a greylisting implementation for the Qmail mail server was released a couple of days ago.

    more »
  • Charly's Column

    The Postfix Policyd plugin fights spam using techniques such as greylisting, source detection, volume measurements, blacklisting, and HELO rotation detection.

    more »
  • Bot_Attack

    While going about his normal duties, Linux Magazine author Charly Kühnast was hit with a mean attack. Charly’s separate anti-spam server, which sits in front of his mail server, saved him from the mail storm.

    more »
  • Milter Manager 1.0.0 Combines Anti-Spam Filters

    Milter Manager, a program for mail filter interfaces to mail servers, is now in its first stable version 1.0.0. It allows combining multiple mail filters.

    more »
comments powered by Disqus

Visit Our Shop

Trial Subscription

Digital Subscription

Subscribe

Direct Download

Read full article as PDF:

Price $2.95

News

Tag Cloud

Administration Community Events Hardware Linux Linux New Media Linux Pro Magazine Mobile Programming Software Ubuntu Web Development Windows free software open source