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 firstname.lastname@example.org 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 email@example.com.