This book is primarily intended for system administrators who also administer email. But not all Unix systems are managed by administrators. Many are managed by programmers, network engineers, and even inexperienced users. It is our hope that this book satisfies all of you, no matter what your level of experience.
The true beginner should begin with Part I, skipping ahead as needed.
The beginning system administrator should probably start with Part I to learn how to build and install sendmail, then read Part II for help in understanding how to administer sendmail. Note that Part II and Part III will reveal answers to many nagging questions that seem to be otherwise unanswered.
Unix gurus and sendmail specialists should find Part III to be of value (even Eric keeps a copy on his desk). In it, every arcane detail of sendmail is listed alphabetically. For example, in Part III you’ll find a single chapter dedicated to options, with every option listed and explained.
No matter what your level of expertise, the sheer size of this book forces us to assume that you are familiar with the day-to-day system workings of Unix. If you aren’t, you must learn Unix elsewhere.