Book Image

Linux Email

Book Image

Linux Email

Overview of this book

Many businesses want to run their email servers on Linux for greater control and flexibility of corporate communications, but getting started can be complicated. The attractiveness of a free-to-use and robust email service running on Linux can be undermined by the apparent technical challenges involved. Some of the complexity arises from the fact that an email server consists of several components that must be installed and configured separately, then integrated together. This book gives you just what you need to know to set up and maintain an email server. Unlike other approaches that deal with one component at a time, this book delivers a step-by-step approach across all the server components, leaving you with a complete working email server for your small business network. Starting with a discussion on why you should even consider hosting your own email server, the book covers setting up the mail server. We then move on to look at providing web access, so that users can access their email out of the office. After this we look at the features you'll want to add to improve email productivity: virus protection, spam detection, and automatic email processing. Finally we look at an essential maintenance task: backups. Written by professional Linux administrators, the book is aimed at technically confident users and new and part-time system administrators. The emphasis is on simple, practical and reliable guidance. Based entirely on free, Open Source software, this book will show you how to set up and manage your email server easily.
Table of Contents (15 chapters)
Linux E-mail
Credits
About the Authors
About the Reviewers
Preface

Stopping spam and other unwanted messages


This section will discuss the various methods Postfix provides to help stop unwanted messages. Spam, or unsolicited commercial e-mail, is perhaps the biggest problem that e-mail server administrators face, but there may also be other kinds of messages that one does not want to receive.

Postfix by itself will not stop all spam, but it can catch many spam messages. For some people this may be adequate, but if you need to fight large volumes of spam you may need a tool such as SpamAssassin, described in Chapter 8. Even if you use SpamAssassin, Postfix's own lightweight methods can help reduce the load on the server by rejecting the messages before they even reach SpamAssassin.

Postfix's anti-spam methods: An overview

There is no silver bullet to stop all spam, but Postfix provides a number of methods that you can use to help the situation:

  • SMTP restrictions: SMTP restrictions let you define rules that control whether or not a message is accepted by...