'sendmail' is one of those classic O'Reilly books that have undertaken legend status. Now in it's 4th revision, there really isn't much new that can be said about this book. With editions having been released in 1993, 1997, 2002, and now 2007, this book is required reading for anyone that is in charge of mail routing responsibilities at their company. With 26 chapters, 1200+ pages and content that is spot on, this is a must buy for anyone that is using sendmail on a daily basis.

***** HIGHLY RECOMMENDED

Bryan Costales, George Jansen, and Claus Afsmann with Gregory Neil Shapiro provide the 4th updated edition of SENDMAIL, a top pick for any advanced programmer's library, especially those featuring books solid on networking. SENDMAIL first appeared in 1993: this version covers 8.10 and 8.14 of the email routing program and is a 'must' for programmers who would keep up with the latest.

For years O'Reilly has been the last word in exhaustively explaining Unix utilities, and the first edition of this book goes back to 1993. The reason to upgrade to this fourth edition is that it covers version 8.14 of sendmail, which is now the current release. This new edition looks much like past editions, but it also contains in Appendix B the many improvements of sendmail since the previous edition and in which section of the book you can find each improvement covered.

Even though sendmail is an old program, it is still useful. It is mature, reliable, and scalable. Unfortunately, its ability to be configured for all kinds of uses and users has made it much more complex. Sendmail is capable of transporting mail between a wide variety of machines. Consequently, its configuration file is very flexible, allowing a single binary to be distributed to many machines, where the configuration file can be customized to suit particular needs. This configurability contributes to making sendmail complex. This book does a good job of sorting out just about all of the possibilities and questions you might have. The following is the table of contents, not currently shown on the product description page:

Chapter 1. Some Basics

Part 1: Administration
Chapter 2. Download, Build, and Install
Chapter 3. Tune sendmail with Compile-Time Macros
Chapter 4. Maintain Security with sendmail
Chapter 5. Authentication and Encryption
Chapter 6. The sendmail Command Line
Chapter 7. How to Handle Spam
Chapter 8. Test Rule Sets with -bt
Chapter 9. DNS and sendmail
Chapter 10. Build and Use Companion Programs
Chapter 11. Manage the Queue
Chapter 12. Maintain Aliases
Chapter 13. Mailing Lists and forward
Chapter 14. Signals, Transactions, and Syslog
Chapter 15. Debug sendmail with -d

Part 2: Configuration Reference
Chapter 16. Configuration File Overview
Chapter 17. Configure sendmail with m4
Chapter 18. The R (Rules) Configuration Command
Chapter 19. The S (Rule Sets) Configuration Command
Chapter 20. The M (Mail Delivery Agent) Configuration Command
Chapter 21. The D (Define a Macro) Configuration Command
Chapter 22. The C and F (Class Macro) Configuration Commands
Chapter 23. The K (Database-Map) Configuration Command
Chapter 24. The O (Options) Configuration Command
Chapter 25. The H (Headers) Configuration Command
Chapter 26. The X (Milters) Configuration Command

Part 3: Appendixes
Appendix A. The mc Configuration Macros and Directives
Appendix B. What's New Since Edition 3