Eric Allman Speaks
I have to admit that I'm surprised by how well sendmail has succeeded. It's not because of a large marketing organization or a deep-pockets budget. I think there are three reasons.
took the approach that it should try to accept, clean up, and deliver even very "crufty" messages instead of rejecting them because they didn't meet some protocol. I felt this was important because I was trying to gateway UUCP to the ARPAnet. At the time, the ARPAnet was small, UUCP was
Second, I limited
configuration file was flexible enough to adapt to a
And, of course, it didn't hurt that it was free, available at the right time, and did what needed to be done.
is complex because the world is complex. It is dynamic because the world is dynamic. Someday
, like X11, will die ”but I'm not holding my
When I started reviewing Bryan's first-edition manuscript, I had been avoiding any major work on
. But then I started reading about various petty
We've divided this book into one introduction and four
Chapter 1 will be of special help to the new
Part I covers compilation, installation, and configuration of sendmail , and the other programs supplied with the sendmail source.
Part II for more
Part III covers all aspects of the configuration file in detail, and includes complete reference sections.
Part IV contains the appendices.
Audience and Assumptions
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
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
, then read Part II for help in understanding how to administer
. Note that Part II and Part III will reveal answers to many nagging questions that seem to be
Unix gurus and
specialists should find Part III to be of value (even Eric keeps a copy on his desk). In it, every arcane detail of
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.