Top critical review
Great overview, but needs an update.
on 5 December 2014
The usual O'Reilly high standard of technical writing - concise, well-explained, with clear diagrams and the right mix of overviews, technical information and reference.
Really good explanation of Postfix's architecture, and how to develop for Postfix.
However, in 2014, it's in dire need of a revision. Postfix has progressed a lot since this book was written and the reference is lacking some fairly important areas.