47 Stopping Spam with SpamAssassin

Technique

Save Time By

Using SpamAssassin to screen your e-mail

Configuring SpamAssassin with the Configuration Generator

Setting up SpamAssassin as a filter for your Evolution e-mail client

Updating your rule set with RulesDuJour

Spam is a major waste of time and resources. The kind of spam we’re talking about isn’t the pink stuff in a can — it’s junk e-mail. (We wanted to include a technique about the edible Spam, but our editors

said no: See www.spam.com for your daily dose of pink meat.) Unsolicited commercial e-mail not only takes up your valuable time reading and weeding through it, but also ties up your CPU and consumes valuable storage space on your server. And it’s downright annoying. Fortunately, you can reduce the amount of spam you receive with the help of a great tool called SpamAssassin.

SpamAssassin has several mechanisms for deciding what is and isn’t spam:

Rule set that computes a spam threshold: A numerical score identifies an e-mail message as spam or ham (ham is the opposite of spam — we’re not making this up).

Bayesian filtering: Bayesian filtering figures out what spam looks like as it reads your e-mail. It learns and evolves to keep up with spammers’ tactics.

Character-set and language sensitivity: You can specify languages and character sets that should be considered spam. (For example, unless you’re conversing in Russian, e-mail composed entirely of Cyrillic characters is likely to be spam.)

In this technique, we introduce you to your new e-mail assistant, SpamAssassin. With the added tool, RulesDuJour, updating your rule sets is a breeze. With up-to-date rule sets, SpamAssassin learns and grows to keep up with the ever-changing antics adopted by spammers, and saves you time and frustration by letting you read the ham without having to wade through the spam.

Installing SpamAssassin

SpamAssassin is an open-source project that screens incoming e-mail for unwanted or commercial e-mail. It’s a smart tool, with ever-evolving rule sets that can keep pace with even the slickest of spammers.

Installing SpamAssassin 357

You can install SpamAssassin from the Fedora or SuSE distribution media or by downloading the latest RPM packages from www.spamassassin.org, the official Web site of SpamAssassin.

Installing from the distribution media

If you’re a Fedora user, the quickest and easiest way to install SpamAssassin is with the Fedora Add or Remove Packages program and the Fedora distribution media. The procedure is similar on SuSE systems except that you use YAST2 (SpamAssassin is well-hidden in Productivity Networking Email Utilities).

Check out Technique 56 for details about downloading and burning your own set of distribution discs.

To install SpamAssassin from the Linux distribution media, follow these steps:

1. Open the Main Menu and choose System Settings Add or Remove Packages. Click the

Forward button.

A scan for currently installed packages begins.

2. When the Add or Remove Packages window opens (see Figure 47-1), scroll down and check the Mail Server box.

3. Click the Details link to the right of the Mail

Server entry to open the Mail Server Package Details window.

4. Check the Spamassassin box to include the package in the installation, as shown in Figure 47-2.

5. Click the Close button, and then in the Add or

Remove Packages window, click the Forward button.

The system update is prepared, and a Package Installation Overview window appears, displaying SpamAssassin and any dependencies (see Figure 47-3).

• Figure 47-1: Check the Mail Servers box.

•Figure 47-2: Check the box next to Spamassassin.

6.Click the Forward button.

The system update begins. When installation is complete, the Package Installation Complete window is displayed.

7.Click the Finish button.