Well Filtered

Simplified Configuration with Webmin

The configuration of SpamAssassin at the console level is not for everyone. The process is also error prone, which can have unpleasant consequences if, for example, the wrong email messages are identified as spam. The control and administration of SpamAssassin is significantly easier with a GUI.

Webmin, a classic among admin tools, provides a SpamAssassin Mail Filter module in the Servers category that makes it easy to create allowed and denied email addresses (Figure 3). To do this, follow the Allowed and Denied Addresses link in the straightforward web interface. The associated form also allows you to import existing address files of established email clients that you explicitly want to exclude from filtering.

Figure 3: The administration of the SpamAssassin filter is considerably simplified with the comfortable Webmin module.

The classification options for the spam assessment are behind the Spam Classification icon. Here you can determine which tests are applied to incoming email and how they are weighted.

Under Message Notification, you can determine what changes are made to email identified as spam. The subject is expanded with the word Spam by default, and the assessment is added to the subject. Other options include adding your own texts and new headers. You can even introduce your own header and body test via the Webmin module. To do so, click the Header and Body Tests link. These tests can also refer to URLs in the message.

The SpamAssassin module can also draw on MySQL and LDAP databases. The import mechanism simplifies data transfer from common storage systems. The module also allows you to edit the SpamAssassin configuration file and the whitelist configuration.

Webmin modules usually always have their own module configuration; the SpamAssassin module included. Follow the Module Config link at the top if, for example, you want to use a different path to the filter configuration or to Procmail.

Because Webmin does not necessarily need be installed on the SpamAssassin server, you can also use the tool for remotely administering the spam filter. You can also set up the interaction with Procmail very easily. To this end, follow the Procmail Spam Delivery link and determine what should happen with the email classified as spam.

SpamAssassin for Windows

Smaller companies in particular may prefer to use Windows computers instead of Linux servers because a specialist is not necessarily required for the administration and maintenance of a system. Even if a local email server is operated onsite (e.g., with the XAMPP package), the question remains as to how to set up filtering.

Software developers JAM Software [5] have ported SpamAssassin to Windows and provide a free and a commercial version of the filter. The basic free version includes the following programs in addition to the Perl run-time environment and various plugins:

• spamassassin.exe: the mail filter
• spamd.exe: SpamAssassin as a server process
• spamc.exe: client to the server process
• sa-update.exe: program to update the filter rules
• sa-learn.exe: trains the Bayesian filter with spam/ham email

Although the installation is easy to perform, you might be a bit disappointed at the lack of a GUI. All actions and settings must be carried out in a terminal or in text files, like the Linux console version (Figure 4).

Figure 4: SpamAssassin is also available in a Windows port; in particular, it can protect Windows mail servers, including Exchange Server using an adapter.

If you want to use SpamAssassin for Windows with Exchange Server, you will need to purchase a special license for the connector. In addition to the free basic version, the developers also offer the SpamAssassin in a Box version which, for example, can use the Windows Event Viewer and for which the developers offer support.

Conclusions

SpamAssassin is a classic among antispam filters and performs its service very reliably. The administrative overhead for setting up, configuring, and maintaining the software is minimal. However, if you do not want to do without a GUI, a suitable solution is available in the form of the Webmin module.