sendmail - Eric Allman

This Nutshell Handbook is far and away the most comprehensive book
ever written on sendmail, the program that acts like a traffic cop in
routing and delivering mail on UNIX-based networks. Although sendmail
is used on almost every UNIX system, it's one of the last great
uncharted territories--and most difficult utilities to learn-- in UNIX system administration.This book provides a complete sendmail tutorial, plus extensive
reference material on every aspect of the program. What's more, it's
authoritative, having been co-authored by Eric Allman, the developer
of sendmail, and Neil Rickert, one of the leading sendmail gurus on
the Net.This book covers both IDA sendmail and the latest version (V8)
from the University of California, Berkeley. It also covers the standard versions available on most systems, such as those found on Sun and DEC/Ultrix workstations.The book is divided into four parts. Part One is a tutorial on
understanding sendmail from the ground up; starting from
an empty file, it has the reader work through exercises, building
a configuration file and testing the results. Part Two covers practical
issues in sendmail administration. Part Three is a comprehensive
reference section, while Part Four consists of appendices and a bibliography.