Language Selection

English French German Italian Portuguese Spanish

Howto: Mail Server with Virtual Users And Domains

Filed under
HowTos

This document describes how to install a mail server based on Postfix that is based on virtual users and domains, i.e. users and domains that are in a MySQL database. I'll also demonstrate the installation and configuration of Courier (Courier-POP3, Courier-IMAP), so that Courier can authenticate against the same MySQL database Postfix uses.

The resulting Postfix server is capable of SMTP-AUTH and TLS and quota (quota is not built into Postfix by default, I'll show how to patch your Postfix appropriately). Passwords are stored in encrypted form in the database (most documents I found were dealing with plain text passwords which is a security risk). In addition to that, this tutorial covers the installation of Amavisd, SpamAssassin and ClamAV so that emails will be scanned for spam and viruses.

The advantage of such a "virtual" setup (virtual users and domains in a MySQL database) is that it is far more performant than a setup that is based on "real" system users. With this virtual setup your mail server can handle thousands of domains and users. Besides, it is easier to administrate because you only have to deal with the MySQL database when you add new users/domains or edit existing ones. No more postmap commands to create db files, no more reloading of Postfix, etc. For the administration of the MySQL database you can use web based tools like phpMyAdmin which will also be installed in this howto. The third advantage is that users have an email address as user name (instead of a user name + an email address) which is easier to understand and keep in mind.

Full Story.

More in Tux Machines

What the Linux Foundation Does for Linux

Jim Zemlin, the executive director of the Linux Foundation, talks about Linux a lot. During his keynote at the LinuxCon USA event here, Zemlin noted that it's often difficult for him to come up with new material for talking about the state of Linux at this point. Every year at LinuxCon, Zemlin delivers his State of Linux address, but this time he took a different approach. Zemlin detailed what he actually does and how the Linux Foundation works to advance the state of Linux. Fundamentally it's all about enabling the open source collaboration model for software development. "We are seeing a shift now where the majority of code in any product or service is going to be open source," Zemlin said. Zemlin added that open source is the new Pareto Principle for software development, where 80 percent of software code is open source. The nature of collaborative development itself has changed in recent years. For years the software collaboration was achieved mostly through standards organizations. Read more

Arch-based Linux distro KaOS 2014.08 is here with KDE 4.14.0

The Linux desktop community has reached a sad state. Ubuntu 14.04 was a disappointing release and Fedora is taking way too long between releases. Hell, OpenSUSE is an overall disaster. It is hard to recommend any Linux-based operating system beyond Mint. Even the popular KDE plasma environment and its associated programs are in a transition phase, moving from 4.x to 5.x. As exciting as KDE 5 may be, it is still not ready for prime-time; it is recommended to stay with 4 for now. Read more

diff -u: What's New in Kernel Development

One problem with Linux has been its implementation of system calls. As Andy Lutomirski pointed out recently, it's very messy. Even identifying which system calls were implemented for which architectures, he said, was very difficult, as was identifying the mapping between a call's name and its number, and mapping between call argument registers and system call arguments. Some user programs like strace and glibc needed to know this sort of information, but their way of gathering it together—although well accomplished—was very messy too. Read more

GNU hackers discover HACIENDA government surveillance and give us a way to fight back

GNU community members and collaborators have discovered threatening details about a five-country government surveillance program codenamed HACIENDA. The good news? Those same hackers have already worked out a free software countermeasure to thwart the program. According to Heise newspaper, the intelligence agencies of the United States, Canada, United Kingdom, Australia, and New Zealand, have used HACIENDA to map every server in twenty-seven countries, employing a technique known as port scanning. The agencies have shared this map and use it to plan intrusions into the servers. Disturbingly, the HACIENDA system actually hijacks civilian computers to do some of its dirty work, allowing it to leach computing resources and cover its tracks. Read more