I picked this up to help me get Postfix running on my Mac - which it did nicely. I doubt any Postfix admin will be disappointed with this book, although it has way more information than I need at this point... Always a good thing when a book answers your questions now and can answer new questions in the future. =)I'm no Postfix expert, but I this book is incredibly detailed and probably doesn't leave anything out. I really like the fact that it doesn't just tip-toe through the config files and options. It goes into a lot of detail, with a lot of instruction and examples. More importantly, it steps you though how to test your configuration to verify any changes you make.The appendix describes how to install Postfix on Debian Linux or Red Hat Linux, so if you need detailed installation instructions for other platforms, you need to look elsewhere. However, once you get Postfix installed, this book will not disappoint.Very well done.