Welcome!

Linux Containers Authors: Elizabeth White, Liz McMillan, Stackify Blog, Pat Romanski, Kevin Benedict

Related Topics: Linux Containers

Linux Containers: Article

qmail

Delivering security and performance

In the area of Mail Transfer Agents (MTAs), most people would look at sendmail as the most popular solution in the open source/Linux arena. However, it's not the only solution. Although postfix is popular with a number of administrators (especially those with multiple domains and many users), qmail is the unknown underdog that the experts use.

John Levine, well-known book author and Internet guru, talks about his new book, qmail, which covers the entire gamut of qmail administration from installation to configuration and filtering.

LWM: Another title in the successful mail-management series. Can you tell me the main benefits of qmail over other MTAs such as sendmail?

John Levine: qmail's two strongest points are security and performance. qmail was designed and written by a computer security geek, and is small enough so that if you want, you can read all the source. There's never been a security bug in qmail, that is, one that lets one user damage another's mail or get access to unauthorized parts of the system.

In the kind of environment for which it was designed, with lots of bandwidth, qmail pumps out mail at a phenomenal rate. Dan Bernstein's original motivation for writing qmail was to get mailing list mail delivered fast, and it does that really well.

qmail has always struck me as complex to set up, but easier to manage in the long term. Is that a fair assessment?

It's not so much that it's complex to set up but that it's utterly different from sendmail. The basic configuration is pretty simple, but it's in a bunch of separate files rather than the barococo majesty of sendmail.cf.

The other problem in setting up qmail is due to its peculiar license that doesn't permit people to redistribute modified versions, so you have to pick up the original 1998 code and patch it to add new stuff. Fortunately, earlier this year several members of the qmail community put together netqmail, which combines qmail with a set of widely used patches and it's all you need.

Spam and UBE are obviously big headaches for managers today. What features does qmail support to help combat this?

Nothing built in, but just about every anti-spam scheme you ever heard of is available as a qmail add-on. Dan offers a program called rbldnsd that uses DNS blocklists like the SBL, and people add spam filters such as procmail, greylists, you name it. qmail's modular structure makes it easy to splice new features in.

Do you think there is a solution to spam, or is it something we'll all just have to live with?

There's certainly no magic bullet, but I think that combinations of technical and legal measures will eventually get it under control, although never make it completely go away.

You're a long-time author, well known for a large number of titles and the Internet Gurus group. Can I ask you how you manage the mountains of e-mail you must receive?

It's all standard Unix tools. I use procmail to sort my mail, Pine to read it, and I put most of the mailing lists to local newsgroups so I can read them with trn.

qmail handles a dizzying array of potential delivery and mail routing options. What's the best way to approach a new installation?

Start with a basic installation, then figure out what extra stuff you need. The configuration is mostly driven out of text files so it's easy enough to add new bits to your configuration. You'll also find that once you get some experience with qmail, what you want to add will be more evident.

Migration from an existing setup seems even more complicated. Is there some way of easing the migration from sendmail or postfix?

 Well, there is a chapter in my book on it. You have to figure out what your current setup is doing, then run down the list and make qmail do all the things you care about. I've often found that old sendmail setups have mountains of cruft, and you can throw a lot of it away when you see what your mail system is really doing.

You cover both IMAP and POP in your book. Which do you recommend?

Depends on your usual connection. If it's on a LAN or broadband, IMAP rocks, particularly if you're using one of the Maildir-based IMAP servers (Courier or binc) that supports multiple simultaneous sessions. I can have Pine on my BSD box, Thunderbird on my PC, and Web mail all open at once, and it just works, all viewing the same mailboxes.

On the other hand, if you do dialup, you're still better off with POP since IMAP can be painfully slow over a slow connection.

Could you tell us what we can expect to see from you next?

Internet for Dummies, fabulous all new 10th edition coming next summer.

About John R. Levine

John R. Levine writes, speaks, and consults on the Internet, electronic mail, cybersecurity, and related topics (www.johnlevine.com).

More Stories By Martin C. Brown

Martin C. Brown is a former IT director with experience in cross-platform integration. A keen developer, he has produced dynamic sites for blue-chip customers, including HP and Oracle, and is the technical director of Foodware.net. Now a freelance writer and consultant, MC, as he is better known, works closely with Microsoft as an SME; has a regular column on both ServerWatch.com and IBM's DeveloperWorks Grid Computing site; is a core member of the AnswerSquad.com team; and has written books such as XML Processing with Perl, Python and PHP, and the Microsoft IIS 6 Delta Guide.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@ThingsExpo Stories
Consumers increasingly expect their electronic "things" to be connected to smart phones, tablets and the Internet. When that thing happens to be a medical device, the risks and benefits of connectivity must be carefully weighed. Once the decision is made that connecting the device is beneficial, medical device manufacturers must design their products to maintain patient safety and prevent compromised personal health information in the face of cybersecurity threats. In his session at @ThingsExpo...
"We're a cybersecurity firm that specializes in engineering security solutions both at the software and hardware level. Security cannot be an after-the-fact afterthought, which is what it's become," stated Richard Blech, Chief Executive Officer at Secure Channels, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that Grape Up will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct. 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company specializing in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the U.S. and Europe, Grape Up works with a variety of customers from emergi...
Detecting internal user threats in the Big Data eco-system is challenging and cumbersome. Many organizations monitor internal usage of the Big Data eco-system using a set of alerts. This is not a scalable process given the increase in the number of alerts with the accelerating growth in data volume and user base. Organizations are increasingly leveraging machine learning to monitor only those data elements that are sensitive and critical, autonomously establish monitoring policies, and to detect...
SYS-CON Events announced today that Massive Networks will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Massive Networks mission is simple. To help your business operate seamlessly with fast, reliable, and secure internet and network solutions. Improve your customer's experience with outstanding connections to your cloud.
Everything run by electricity will eventually be connected to the Internet. Get ahead of the Internet of Things revolution and join Akvelon expert and IoT industry leader, Sergey Grebnov, in his session at @ThingsExpo, for an educational dive into the world of managing your home, workplace and all the devices they contain with the power of machine-based AI and intelligent Bot services for a completely streamlined experience.
Because IoT devices are deployed in mission-critical environments more than ever before, it’s increasingly imperative they be truly smart. IoT sensors simply stockpiling data isn’t useful. IoT must be artificially and naturally intelligent in order to provide more value In his session at @ThingsExpo, John Crupi, Vice President and Engineering System Architect at Greenwave Systems, will discuss how IoT artificial intelligence (AI) can be carried out via edge analytics and machine learning techn...
With tough new regulations coming to Europe on data privacy in May 2018, Calligo will explain why in reality the effect is global and transforms how you consider critical data. EU GDPR fundamentally rewrites the rules for cloud, Big Data and IoT. In his session at 21st Cloud Expo, Adam Ryan, Vice President and General Manager EMEA at Calligo, will examine the regulations and provide insight on how it affects technology, challenges the established rules and will usher in new levels of diligence a...
In the enterprise today, connected IoT devices are everywhere – both inside and outside corporate environments. The need to identify, manage, control and secure a quickly growing web of connections and outside devices is making the already challenging task of security even more important, and onerous. In his session at @ThingsExpo, Rich Boyer, CISO and Chief Architect for Security at NTT i3, discussed new ways of thinking and the approaches needed to address the emerging challenges of security i...
SYS-CON Events announced today that Datera, that offers a radically new data management architecture, has been named "Exhibitor" of SYS-CON's 21st International Cloud Expo ®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Datera is transforming the traditional datacenter model through modern cloud simplicity. The technology industry is at another major inflection point. The rise of mobile, the Internet of Things, data storage and Big...
An increasing number of companies are creating products that combine data with analytical capabilities. Running interactive queries on Big Data requires complex architectures to store and query data effectively, typically involving data streams, an choosing efficient file format/database and multiple independent systems that are tied together through custom-engineered pipelines. In his session at @BigDataExpo at @ThingsExpo, Tomer Levi, a senior software engineer at Intel’s Advanced Analytics ...
SYS-CON Events announced today that Datera will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Datera offers a radically new approach to data management, where innovative software makes data infrastructure invisible, elastic and able to perform at the highest level. It eliminates hardware lock-in and gives IT organizations the choice to source x86 server nodes, with business model option...
With 10 simultaneous tracks, keynotes, general sessions and targeted breakout classes, Cloud Expo and @ThingsExpo are two of the most important technology events of the year. Since its launch over eight years ago, Cloud Expo and @ThingsExpo have presented a rock star faculty as well as showcased hundreds of sponsors and exhibitors! In this blog post, I provide 7 tips on how, as part of our world-class faculty, you can deliver one of the most popular sessions at our events. But before reading the...
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. CA Technologies helps customers succeed in a future where every business - from apparel to energy - is being rewritten by software. From planning to development to management to security, CA creates software that fuels transformation for companies in the applic...
SYS-CON Events announced today that GrapeUp, the leading provider of rapid product development at the speed of business, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company, specialized in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market acr...
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
From 2013, NTT Communications has been providing cPaaS service, SkyWay. Its customer’s expectations for leveraging WebRTC technology are not only typical real-time communication use cases such as Web conference, remote education, but also IoT use cases such as remote camera monitoring, smart-glass, and robotic. Because of this, NTT Communications has numerous IoT business use-cases that its customers are developing on top of PaaS. WebRTC will lead IoT businesses to be more innovative and address...
In his opening keynote at 20th Cloud Expo, Michael Maximilien, Research Scientist, Architect, and Engineer at IBM, discussed the full potential of the cloud and social data requires artificial intelligence. By mixing Cloud Foundry and the rich set of Watson services, IBM's Bluemix is the best cloud operating system for enterprises today, providing rapid development and deployment of applications that can take advantage of the rich catalog of Watson services to help drive insights from the vast t...
SYS-CON Events announced today that Elastifile will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Elastifile Cloud File System (ECFS) is software-defined data infrastructure designed for seamless and efficient management of dynamic workloads across heterogeneous environments. Elastifile provides the architecture needed to optimize your hybrid cloud environment, by facilitating efficient...