Defeat spam with Postgrey by greylisting and whitelisting incoming mail
Hail Mail
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
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
AlmaLinux 10.0 Beta Released
The AlmaLinux OS Foundation has announced the availability of AlmaLinux 10.0 Beta ("Purple Lion") for all supported devices with significant changes.
-
Gnome 47.2 Now Available
Gnome 47.2 is now available for general use but don't expect much in the way of newness, as this is all about improvements and bug fixes.
-
Latest Cinnamon Desktop Releases with a Bold New Look
Just in time for the holidays, the developer of the Cinnamon desktop has shipped a new release to help spice up your eggnog with new features and a new look.
-
Armbian 24.11 Released with Expanded Hardware Support
If you've been waiting for Armbian to support OrangePi 5 Max and Radxa ROCK 5B+, the wait is over.
-
SUSE Renames Several Products for Better Name Recognition
SUSE has been a very powerful player in the European market, but it knows it must branch out to gain serious traction. Will a name change do the trick?
-
ESET Discovers New Linux Malware
WolfsBane is an all-in-one malware that has hit the Linux operating system and includes a dropper, a launcher, and a backdoor.
-
New Linux Kernel Patch Allows Forcing a CPU Mitigation
Even when CPU mitigations can consume precious CPU cycles, it might not be a bad idea to allow users to enable them, even if your machine isn't vulnerable.
-
Red Hat Enterprise Linux 9.5 Released
Notify your friends, loved ones, and colleagues that the latest version of RHEL is available with plenty of enhancements.
-
Linux Sees Massive Performance Increase from a Single Line of Code
With one line of code, Intel was able to increase the performance of the Linux kernel by 4,000 percent.
-
Fedora KDE Approved as an Official Spin
If you prefer the Plasma desktop environment and the Fedora distribution, you're in luck because there's now an official spin that is listed on the same level as the Fedora Workstation edition.