A Server (Almost) of Your Own
set postmaster "usera" set no bouncemail set no spambounce poll localhost with protocol POP3 and port 2110 and options no dns: user "maila" there is usera here and wants mda "/usr/bin/procmail -d %T" options fetchall password "MAILA'S VPS PASSWORD"
# The person who gets all mail for userids < 1000 # Make this empty to disable rewriting. root=postmaster # The place where the mail goes. The actual machine # name is required; no MX records are consulted. mailhub=localhost:2525 # The full hostname hostname=localhost # The "From" line sender address will override any # settings here. FromLineOverride=YES
Finally, note that you need to set up the SSH tunnel again every time you reboot your workstation. There are many ways to automate the process, but it is beyond the scope of this article to discuss them.
The Fedora Linux distribution provides a Web-based e-mail interface that requires very little work to configure. It is based on SquirrelMail and Apache. Web mail is an easy way to support Windows clients. It also does not require shell access on the VPS.
First, install SquirrelMail:
[root@myvps ~]# up2date --install squirrelmail
This process also installs several other packages that SquirrelMail requires. Next, enable secure https access by installing mod_ssl:
[root@myvps ~]# up2date --install mod_ssl
You must disable unsecure http access to SquirrelMail. Edit the file /etc/httpd/conf.d/squirrelmail.conf, and append the following lines:
<LocationMatch "/webmail"> SSLRequireSSL </LocationMatch>
Now, start the Apache Web server:
[root@myvps ~]# /etc/init.d/httpd start
Connect to https://MY.VPS.IP.ADDRESS/webmail. Your browser will warn you about the SSL certificate—just accept it permanently, and you will not be warned again. The only way to avoid this error altogether is to use a certificate signed by a recognized Certificate Authority (CA). The CA will need to verify your identity and also will charge an annual fee for signing the certificate.
After accepting the certificate, you should be able to log in as any of the mail users that you have created earlier. If a particular mail user—for example mailb—does not need shell access, disable it with the following command:
[root@myvps ~]# usermod -s /sbin/nologin mailb
Do not forget to add the Apache Web server to your startup environment:
[root@myvps ~]# chkconfig --level 345 httpd on
Your Web mail users should click on the Options link in the SquirrelMail interface and configure their account information. Otherwise, SquirrelMail will format their messages with something like email@example.com in the From field. This certainly will confuse anyone who receives such a message.
This article has covered one of the most difficult aspects of switching to a VPS account—setting up your e-mail. As you have seen, e-mail service is provided by a collection of several different programs working together. There are many other ways to configure this service. Unfortunately, it would require a lengthy book to describe and compare them all. This article tries to provide a simple solution with good security that a new VPS user can implement quickly.
Welcome to the world of VPS hosting—the server that is (almost) your own.
The author wishes to acknowledge Sean Reifschneider and Evelyn Mitchell of tummy.com, LTD., for generously providing a VPS account used to test the examples presented here, as well as their valuable comments on this article.
Resources for this article: /article/9380.
George Belotsky is a software architect who has done extensive work on high-performance Internet servers, as well as hard real-time and embedded systems. His technology interests include C++, Python and Linux. He is also the author of the Flightdeck-UI Open Source Project, which uses the ideas from aircraft instrumentation to implement computer user interfaces. You can reach George at firstname.lastname@example.org.
Practical Task Scheduling Deployment
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
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- The Firebird Project's Firebird Relational Database
- Stunnel Security for Oracle
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- SUSE LLC's SUSE Manager
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Doing for User Space What We Did for Kernel Space
- Google's SwiftShader Released
- SuperTuxKart 0.9.2 Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide