The authors have taken the time to clearly answer the key questions that are of real practical value. There is no excessive or superflous material here that, although may good to know, won't divert attention from the topic of configuring a solid MTA. The book is very well focused and the authors' hard work is obvious. There are sections where someone else may have left good enough alone but they went the extra mile to make sure that this book answered the important questions fully.
"The Book of Postfix" starts with "A Postmaster's Primer To Email" and continues through all of the key topics in a sensible progression so that even if you are fairly new to administering email you are taught in a sequential manner that promotes understanding. The comprehensive list of topics encompasses single and multiple domain servers, dial-ups, SMTP restrictions, internal and external content filters, mail gateways, SMTP proxy, SMTP authentication, SASL, LDAP, SQL integration, Transport Layer Security, chroots, rate limiting, performance tuning, and trouble shooting. It covers a good amount of ground.
The numerous "NOTE" and "CAUTION" sections provide great additional detail to real world scenarious that I found extremely relevant and useful. For each topic there is also an invaluable "TESTING" section so that you can verify for yourself that you are in fact getting the expected behavior. The imperative topic of security is always kept in mind in the confugrations and the accompanying diagrams and flow charts do an excellent job of enhancing the text and providing extra clarity.
As a pratical test I followed the text to implment SMTP server side authentication using Cyrus SASL2 libraries. Now this somewhat complex topic has consistently haunted many in the Postfix user community, but by following the reference, things went pretty much without a hitch.
Unless you are a Postfix guru you should own this book if you administer servers running Postfix. The explanations of how Postfix works and how to configure it are very clear and easy to understand. Following the Postfix-users maillist can sometimes be intimidating and confusing as experts are many times talking to their peers with language that lower experienced users struggle to understand. I found that this book did a great job of putting things in easy to understand terms and the biggest message I have is that this book is practical, practical and PRACTICAL. I very much appreciate having a copy.
About the Author: Peter O'Hara joined Guardian Digital in May 1999 with more than 20 years of diverse expertise in Unix/Linux systems in the financial and telecommunications markets. O'Hara is responsible for managing the Internet software development and Internet communications/messaging efforts at Guardian Digital. O'Hara has held a wide range of roles as in both implementation and development. His experience includes Naval Systems Engineering at AT&T, trading support at Kidder Peabody and Merrill Lynch in New York and the worldwide data center for UPS.