This new edition of sendmail covers sendmail Version 8.8 from Berkeley and the standard versions available on most systems. It 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. In addition to Version 8.8, it covers earlier versions available on many systems, such as those found on Sun workstations. Part One is a tutorial on understanding sendmail; Part Two covers the building, installation, and m4 configuration of sendmail; Part Three covers practical issues in sendmail administration; Part Four is a comprehensive reference section; and Part Five consists of appendices and a bibliography. In this second edition an expanded tutorial demonstrates hub's cf file and nullclient.mc. Other new topics include the

Bryan Costales is director of technology with Mercury Mail in Denver, Colorado. Always at the cutting edge, he telecomutes from his home in Laramie, Wyoming. He has been active in system administration for over fifteen years and has been writing articles and books about computer software for over ten years. His most notable books are C from A to Z (Prentice Hall), Unix Communications (Howard Sams), and, of course, sendmail (O'Reilly & Associates). In his rare free time, he dreams of sailing the Gulf coast and writes fiction with a group called Make Believe Sailors. Eric Allman is the original author of sendmail. While working at the University of California, he got involved with the early UNIX effort at Berkeley. His first experiences with UNIX were with 4th Edition, and he still has the manuals to prove it (and has been accused of being a pack rat because of it). Over the years, he wrote a number of utilities that appeared with various releases of BSD, including the -me macros, tset, trek, syslog, vacation, and of course sendmail. Besides working on the INGRES database management project and the Mammoth infrastructure project at Berkeley, Eric worked on window systems at the International Instituted for Applied Systems Analysis in Austria, Britton Lee (later Sharebase) doing database user and application interfaces, and at the International Computer Science Institute, contributing to the Ring Array Processor project for neural-net-based speech recognition. He also co-authored the C Advisor column for Unix Review for several years. Eric has been accused of working incessantly, enjoys writing with fountain pens, and collects wines, which he stashes in the cellar of the house that he shares with Kirk McKusick, his partner of 17 and-some-odd years. He is also treasurer of USENIX Association.