Many businesses want to run their e-mail 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 e-mail service running on Linux can be undermined by the apparent technical challenges involved. Some of the complexity arises from the fact that an e-mail 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 e-mail 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 e-mail server for your small business network.
Chapter 1: Linux and E-mail Basics takes you through the essential elements of a Linux e-mail server and the network and mail protocols that make e-mail possible. Like it or not, running a Linux e-mail server does require some understanding of the underlying networking, and this chapter is where you will start to get that understanding. This chapter explains the benefits and disadvantages of running your own e-mail server and provides some guidance on hardware sizing for a typical organization.
Chapter 2: Setting Up Postfix speaks about basic Postfix setup. Postfix is our chosen Mail Transfer Agent (MTA), which forms the heart of any e-mail server. The MTA is responsible, among other things, for moving messages between the various mail servers on the Internet.
Chapter 3: Incoming mail with POP and IMAP covers what to do with incoming e-mails. It will show you how to set up IMAP and POP access to mailboxes. This means users will be able to send and receive messages using their familiar e-mail clients.
Chapter 4: Providing Webmail Access shows how to set up webmail access using SquirrelMail. This will give users an easy, out-of-office access to their e-mail.
Chapter 5: Securing Your Installation looks at how your installation can be secured to prevent misuse of your users' data and the e-mail facility itself.
Chapter 6: Getting Started with Procmail discusses the basics of Procmail and gets you familiar with the various files that Procmail uses to load recipes, the core principles of filtering, and the options available.
Chapter 7: Advanced Procmail explores Procmail and explains a large number of services and a large amount of functionality that it can provide in getting mail under control. It also discusses the advanced features of Procmail and their benefits.
Chapter 8: Busting Spam with SpamAssassin shows the use of SpamAssassin in conjunction with Procmail to filter out the wide range of spam that afflicts the modern e-mail user.
Chapter 9: Antivirus Protection shows another way to protect users from rogue e-mail—this time the spread of e-mail viruses. Using ClamAV you can scan mail for viruses and schedule tasks to maintain an up-to-date antivirus database.
Chapter 10: Backing up your System will show you how to protect all your hardwork by backing up not only the e-mail itself, but also all of the configuration options that make up your e-mail server. Examples are provided to create an automated backup schedule to minimize data loss. Of course, you'll also learn how to restore data from these backups.
This book is aimed at beginner or intermediate level System Administrators in small businesses, who want to set up a Linux-based e-mail server without spending a lot of time in becoming expert in individual applications.
Basic knowledge of Linux is also expected.
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, along with an explanation of their meaning.
Code words in text are shown as follows: " The configuration file entry that you need to modify is DatabaseMirror.
A block of code is set as follows:
## ## Example config file for freshclam ## Please read the freshclam.conf(5) manual before editing this file. ## This file may be optionally merged with clamd.conf. ##
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
$ grep score.*BAYES /usr/share/spamassassin/* /etc/mail/spamassassin/* ~/.spamassassin/local.cf
Any command-line input or output is written as follows:
# ls -al /etc/init.d/clamsmtpd
New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Save the file using the browser (normally, the File menu has a Save as option)."
Note
Tips and tricks appear like this.
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