Postfix

Andy Murren contributed this review of Richard Blum's Postfix. Powering mail delivery may not be as sexy as programming in exotic new languages, but it sure is important -- Andy gives you the scoop here on how well Postfix (and Postfix) do at the task.

Postfix author Richard Blun pages 542 publisher Sams rating 8 reviewer Andy Murren ISBN 0-672-32114-9 summary Guide to setting up and running Postfix as your MTA.

Postfix is a complete Mail Transfer Agent (MTA) that is meant to be a replacement for Sendmail. Wietse Venema, who works at the IBM Watson Research Center, wrote the program and released it under the IBM Public License. Richard Blum has targeted this book at Intermediate to Advanced users, but he has enough basic information so that even an MS Exchange administrator with no Unix background can get Postfix running quickly.

The book is broken into three sections:

1. Introduction to E-Mail Services and Postfix
2. Installing and Configuring Postfix
3. Advanced Postfix Server Topics

Part I is a nice overview of email, how to use Postfix, how Postfix works and a comparison of Postfix and Sendmail. In chapter 3 'Server Requirements for Postfix' an overview of Unix and Unix commands are covered along with an introduction to bash, gcc and make to bring the non-Unix user up to speed with the tools that they will need.

The chapter on DNS starts by covering the origins of DNS and the basics of how it works. Blum then gives us an explanation of DNS records and how to set them up, including the all-important MX (Mail Exchanger) record. He then gives a brief discussion on how to set up the resolv.conf, hosts and hosts.conf files. The chapter concludes with a quick look at the host, nslookup and dig programs. This chapter serves as a quick reference on getting DNS up and running on a Unix box.

Part II is a detailed section that is the heart of the book. How to set up Postfix is laid out in detail from how to install (both from an RPM file and from source), to configuring it, to logging and blocking UCE/UBE.

One of the sections of the book I was drawn to was on how to set up Postfix as an internal and external mail server for the Small Office environment. This could be for branch offices of a large company (such as insurance offices) or for a Small Office / Home Office (SOHO) that does not have a full time Internet connection. Blum explains how to set up the server for dial-up to send and retrieve mail, and how to run the mail server on the same box as your firewall.

The chapter 'Migrating from Sendmail to Postfix' is a short step-by-step on how and what to convert from Sendmail to Postfix. Since Postfix was designed to do this easily the chapter is shorter than might be expected (only 20 pages).

Rounding out Part II is a chapter on the Maildir mailbox format and a chapter on using an external MDA. The chapter on using an external MDA is a good example of why I like this book. Here is the full Table of Contents for the chapter:

1. Using MDA Programs with Postfix

1. What is a Mail Delivery Agent

1. Automatic Mail Filtering

1. Automatic Mail Replying

1. Automatic Program Initialization by Mail

1. Using an External MDA Program with Postfix

1. Configuring the main.cf file

1. Watching MDA Programs in the Postfix Log

1. The procmail MDA Program

1. Installing procmail

1. The procmail Command Line

1. User-Defined procmail Actions

1. Summary

In this chapter Blum gives a nice quick How-To on procmail. While it is not a full treatment of procmail it has enough information to download, compile, install, configure and run procmail. Coupled with the brief lessons on Unix, gcc, make and bash in the first section, an MS Exchange administrator on their first attempt in the Unix world is provided enough information to get procmail working as the MDA for their new Postfix MTA.

Section III covers advanced server topics including using MySQL, OpenLDAP and Majordomo with Postfix. Like the section on procmail, Blum covers installing and configuring each of these applications and how to make Postfix work with them. Chapter 20 covers POP3 and IMAP, which then leads nicely into the next chapter on SqWebMail. The final chapters are on performance tuning and troubleshooting.

Overall I have found this to be a well-written book that addressed several questions that I had about configuring and using Postfix (such as the SOHO section). It is clear, direct and covers each topic to a level that I found comfortable. For some people this book will be too advanced but that should not be anyone who has a working knowledge of mail servers or of Unix. I would recommend this book for someone who has started to use or wants to migrate to using Postfix.

My major complaint about this book is the price, $49.99. As much as I liked this book, 'Practical UNIX and Internet Security' was more densely packed with information and only cost $39.95.

Table of Contents

1. Introduction

Introduction to E-Mail Services and Postfix

1. E-Mail Services
2. Postfix Services
3. Server Requirements for Postfix
4. DNS and Postfix
5. SMTP and Postfix

Installing and Configuring Postfix

1. Installing Postfix
2. The master.cf Configuration File
3. The main.cf Configuration File
4. Postfix Lookup Tables
5. Using Postfix
6. Using Postfix as an ISP Mail Server
7. Using Postfix as an Office Mail Server
8. Postfix Server Administration
9. Migrating from Sendmail to Postfix
10. Using the Maildir Mailbox Format
11. Using MDA Programs with Postfix

Advanced Postfix Server Topics

1. Using MySQL with Postfix
2. Using OpenLDAP with Postfix
3. Using Majordomo with Postfix
4. Using POP3 and IMAP with Postfix
5. Using SqWebMail with Postfix
6. Performance Tuning Postfix
7. Common Postfix Problems

You can purchase this book at Fatbrain.

Comments

Speed, Maybehaps?

[Christopher B. Brown]

If you're running a personal server, it's not vitally important, but if the mail server is processing thousands of messages a day, it can be significant.

I personally like Postfix because:

• It's pretty easy to configure.

  If your needs are simple, and you need only set up a DMsomehost.to.forward.to entry for Sendmail, Sendmail's easy to configure, but things instantly get a whole lot hairier.

  And I've never had good success with EXIM, and every time I've configured qmail it has been a hassle.

• Like qmail, it supports Maildir, which is presently handy since mail is, at the moment, being delivered to an NFS-mounted directory. Sendmail wouldn't be happy, but Postfix is.
• Postfix should be more resistant to hackers than Sendmail or Exim.

  It seems dangerous to compare Postfix to qmail; spectacular flame wars have broken out between the respective authors...