The Sysadmin’s Daily Grind: Policyd
TURNED DOWN!
The Postfix Policyd plugin fights spam using techniques such as greylisting, source detection, volume measurements, blacklisting, and HELO rotation detection.
Charly Kühnast is a Unix System Manager at the data-center in Moers, near Germany’s famous River Rhine. His tasks include ensuring firewall security and availability and taking care of the DMZ (demilitarized zone). I’ve added many bits and bobs to my tried and trusted Postfix in the course of the years – Spamassassin and virus filters, for example. The latest member in the exclusive club of Postfix add-ons is Policyd. The Policyd tool does not use the content_filter mechanism to integrate with Postfix, in contrast to many other external tools. Instead, Policyd prefers the check_policy_service, which is available in Postfix 2.2 or newer. This gives me the ability to slot Policyd into my existing ruleset at a location that makes sense. I don’t need to send spam that has been rejected for other reasons to the policy daemon. The current release of the Policyd C program is version 1.73. You can download Policyd from [1], and installing the daemon is easy. After unpacking, just enter gmake build gmake install in the policyd directory. MySQL is also required. Policyd gives you a SQL script that automatically creates the required tables. To finish off, you need to create a cron job:
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
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
-
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.
-
New Steam Client Ups the Ante for Linux
The latest release from Steam has some pretty cool tricks up its sleeve.
-
Gnome OS Transitioning Toward a General-Purpose Distro
If you're looking for the perfectly vanilla take on the Gnome desktop, Gnome OS might be for you.