What You Need for Using This Book

SpamAssassin and all the tools it uses are available for download from the Internet. Perl, the main prerequisite, is included in all major Linux distributions and available for most Unix-like operating systems. It can be downloaded from http://www.perl.org/get.html. The Perl CPAN module is normally used to install SpamAssassin; all that is required is an Internet connection.

This book covers integrating with four of the most popular MTAs—Sendmail, Postfix, Exim, and Qmail. MTA integration is only a small part of this book, and most of this book will be relevant no matter which MTA is in use. SpamAssassin can be integrated with most MTAs.