Why This Book Is Necessary

King Gordius of Phrygia once created a knot so tangled that no one could undo it. The Gordian knot stayed tangled, or so the story goes, until Alexander the Great came along and took a different approach to untying the knot. With a sweep of his sword, he parted the great knot once and for all.

It would be nice if the knot that is sendmail could be undone with one quick stroke of fresh insight, but, alas, it cannot. Instead, a more mundane approach must be taken, so in this book we untie the hard way, one strand at a time.

But, you might ask, "Why the effort? Doesn't sendmail predate the dawn of computing time? Hasn't the time come to replace sendmail with something new, something better, something modern?" Not so. Age has brought sendmail maturity and reliability. The sendmail program has withstood the test of time because it is more than just a program, it is a philosophy: a general-purpose, internetwork mail-routing facility with the flexibility and configurability to solve the mail-routing needs of all sites large or small, complex or simple.

These strengths of sendmail are also its weaknesses. Configurability has bred complexity. The sendmail program is difficult to configure and even more difficult to understand. Its configuration file, for example, can be positively frightening. But don't despair. With this book in hand, you should be able to configure sendmail to meet any need and bring the days of the sendmail guru to an end.