Swimming with the Spammers

Phillip Tiburcio

For a long time, my various email accounts did their work quietly and effectively; then I began receiving a large volume of spam every day. I was being crushed under the weight of spam, so I fought back with a personal email server built entirely with free tools and reduced my spam intake by 95%. Although this article describes a personal email setup, the tools mentioned can be applied to other environments.

Bill of Materials

My plan was to build a server that would download all my email accounts, scrub them for spam, sort them into appropriate mail folders, then make everything available via imap/ssl or encrypted Webmail. The integration of several free tools makes this possible on my personal Linux server.

Spamassasin and Vipul's Razor scrub mail for spam using a distributed spam-signature Internet hive mind. A free Perl script called Gotmail can download messages from a Hotmail account via HTTP. Another script called Fetchyahoo does the same for any Yahoo account. Fetchmail rounds out the bunch by downloading mail from various POP accounts I've collected through the years, and Squirrelmail provides a Webmail gateway using Apache and PHP. A few procmail rules sort the incoming mail into appropriate subfolders and relegate spam suspects to a separate folder. An old Pentium III machine running Red Hat Linux was pressed into service to act as the foundation for this host of utilities. Any of the various BSD flavors or Solaris would have worked as well.

Network Setup

A DSL connection provides the Internet connection to my home LAN via a Linksys DSL Router. I configured the DSL router to allow inbound SMTP, ssh, http, and https traffic to the Linux machine. Note that some revisions of the Linksys firmware have terrible upload performance unless you tune the Maximum Transmission Unit (MTU) size parameter in its configuration.