We've divided this book into four parts, each addressing a particular aspect of sendmail as a whole.
Part I - A Tutorial
Part One is a tutorial than can serve as either a hands-on, step-by-step introduction to sendmail for the beginner or a succinct review for the more experienced user. Chapter 1, Introduction through Chapter 4, How to Run sendmail form an overview of email in general, and discuss the roles, behavior, and parts of sendmail . Chapter 5, The sendmail.cf File through Chapter 15, Install and Test the client.cf File examine the configuration file in detail. In them, we develop a mini-configuration file, suitable for use on some client workstations. Chapter 16, The null.mc File and m4 and Chapter 17, The Hub's Complex Rules conclude the tutorial, tying up loose ends and transitioning into more complex configuration files.
Part II - Installation
Part Two covers compilation and installation of sendmail . Chapter 18, Compile and Install sendmail shows how to compile and install sendmail from the source. Chapter 19, V8 m4 Configuration shows how to create a configuration file with the m4 (1) configuration technique. Chapter 20, The checkcompat() Cookbook concludes by illustrating the checkcompat () routine.
Part III - Administration
Part Three covers general administration of sendmail for more experienced users. Chapter 21, DNS and sendmail covers DNS in general and MX records specifically. Chapter 22, Security shows how to protect your site from intrusion. Chapter 23, The Queue through Chapter 26, Logging and Statistics round out the picture with details about the queue, aliases, mailing lists, logging, and statistics.
Part IV - Reference
Part Four is the nitty-gritty - a reference section that provides more detail about sendmail than you may ever need. Each chapter is dedicated to a specific aspect of sendmail or its configuration file. Chapter 31, Defined Macros , for example, details defined macros, and includes an alphabetized reference. Chapter 37, Debugging with -d shows all the debugging switches.