Sendmail
ISBN 1-56592-222-0 Price approximately
£35 UK
Bryan Costales with Eric Allman
38 Chapters, 4 appendices and index in 997 pages
Chapter List
| 1 Introduction
2 Have a V8 3 The Roles of Sendmail 4 How to run Sendmail 5 The sendmail.cf file 6 The Mail Hub and Delivery Agents 7 Macros 8 Address and Rules 9 Rule Set 0 10 Rule Set 3 11 Rule Sets 1 ansS= 12 Class 13 Setting Options 14 Headers, Precedence and Trust 15 Install and Test the client.cf file 16 The null.mc File and m4 17 The Hub's Complex Rules 18 Compile and Install sendmail 19 V8 m4 Configuration |
20 The checkcompat() Cookbook
21 DNS and sendmail 22 Security 23 The Queue 24 Aliases 25 Mailing Lists and ~/.forward 26 Logging and Statistics 27 The Configuration File 28 Rules 29 Rule Sets 30 Delivery Agents 31 Defined Macros 32 Class Macros 33 Database Macros 34 Options 35 Headers 36 The Command Line 37 Debugging with -d 38 Rule-Set Testing with -bt |
SynopsisAppendix A
The client.cf file
Appendix B
Host Status File Internals
Appendix C
The Berkeley DB Database
Appendix D
Sun Enhancements
Sendmail is well known by most people for it's configurability and also it's reliability. It's the MTA that runs large parts of the internet. As we all know, there are many others but sendmail persists even when the system administrator finds that times is hard in the security department. The O'Reilly "bat book" was written by one of the original authors of sendmail. There's plenty of background information here. If you know about the sendmail docs you'll appreciate that some help is required with the cryptic clues in those documents.
Review
The authors of the book are well qualified to comment on the configuration options to do with Sendmail. Eric Allman is the original author of sendmail and has contributed to Berkeley UNIX. Bryan Costales is a Director of Technology with Mercury Mail in Denver. He's also done a lot of system administration and has written books about software for ten years.
Many people have configured and used sendmail. Many have also commented on the fact that a bit more background information would be useful for future use and configuration. The O'Reilly Sendmail book fills that gap and makes a well know mail agent easier to understand at the same time.
The introduction gives a few ideas that didn't occur to me when I first installed sendmail and tried to understand the tortuous configuration options that are available in the package. This situation isn't helped by numerous system admins telling you that configuration is "really easy". Not only that you get the same answer from all people in all countries. Some sympathy would help at times ? This is something that you do get from the book. Yes, I know it's only paper and the printed word but it's more helpful than anything else. A few easy to understand ideas are clearly presented in plain old fashioned english.
Have a V8 gives a few hints that are not found anywhere else. Very useful for the first time novice. The rest of the book goes into running sendmail and what to do with rule sets. The part about administration is also very helpful.
The only thing that I could find wrong with the book was that it gives information about sendmail 8.8. This is of no use to experienced administrators who are now using sendmail 8.10.1 or later. However, it might just be that there may be some sort of security consideration at work here ?
If you are new to sendmail then you will probably find that the bat book is a great deal of help to you.
Colophon
" The animal featured on the front cover of sendmail is the flying fox, a species of fruit bat found chiefly on the islands of the Malay Indonesia archipelago. Of about four thousand species of mammals, nearly one quarter are bats; and of these, 160 are fruit bats. Sixty of the larger fruit bats make up the flying foxes, the largest having a wingspan of five feet. While smaller insect eating bats navigate by echo location, fruit bats depend on a keen sense of sight and smell to perceive their environment. They roost in trees by day, sometimes in extremely large numbers called "camps". They hang from branches by one or both feet, wrap themselves in their wings, and sleep the day away. On hot days, these bats keep cool by fanning themselves with their wings.
Greatly elongated fingers form the main support for the web of skin that has allowed these mammals, alone, to master true flight. At sunset they awaken from their slumber and begin their nocturnal ramblings. A flying fox must flap its wings until it becomes horizontal to the ground before it can let go and fly away. Once airborne, they use their sensitive sense of smell to detect where flowers are blooming or fruits have ripened. Unlike most animals, fruit bats cannot generate vitamin C ( a limitation shared by humans and guinea pigs); thus, it is supplied by fruit in the diet. Flying foxes can range up to forty miles for food. Once a target is located, they are faced with a difficult landing. Sometimes they will simply crash into foliage and grab at what they can; other times they may attempt to catch a branch with their hind feet as they fly over it and then swing upside down; Some will even attempt a difficult half roll under a branch in order to grip it in the preferred position. Once attached and hanging, they will draw the flower or fruit to their mouths with a single hind foot, or the clawed thumbs at the top of each wing. These awkward landings often cause fight among flying foxes, especially upon their return to camp at dawn. A single bad landing can cause an entire bat laden tree to become highly agitated, full of fighting and screaming residents.
People have eaten flying foxes for ages. Samoans, who call the flying fox manu lagi (animal of the heavens) use branches bound to the end of long poles to swat the winged delicacy from the sky. Aborigines in Australia build fires beneath flying fox camps - the smoke stupefies the prey - and use boomerangs to knock the creatures to the ground."
Wonder if this goes on in Los Angeles as well ??
Review by Richard Ibbotson
