Getting Started with Sendmail

To follow a recipe successfully, you must clearly understand the instructions it contains. You must understand the difference between folding and stirring and be able to find the spices when the recipe calls for a pinch of cumin. Just as you must be able to find your way around the kitchen to become a cook, you must know your way around the sendmail distribution in order to build or customize a sendmail configuration.

The directory structure—created by the sendmail source code distribution tarball—contains the tools and ingredients used to build and configure sendmail. The top-level directory created by the tarball is assigned a name that identifies the sendmail version number. At the time of this writing, the current version is sendmail 8.12.9; therefore, the top-level directory is named sendmail-8.12.9. By the time you read this, there will be a newer version of sendmail, and the directory name will reflect that new version number. An ls of the top-level directory shows the following:*

$ ls sendmail-8.12.9 Build doc INSTALL libsmdb mailstats praliases sendmail cf editmap KNOWNBUGS libsmutil Makefile README smrsh contrib FAQ libmilter LICENSE makemap RELEASE_NOTES test devtools include libsm mail.local PGPKEYS rmail vacation

Most of these files and directories are used to compile sendmail. The Build script uses the Makefile to compile sendmail and its utilities. The devtools directory is used to set compiler options, as discussed in Recipes 1.2 to 1.7. The source code is located in aptly named subdirectories. For example, the sendmail source code is in the sendmail directory, the libraries are in directories such as libsm and libsmutil, and the source code of utilities such as makemap and smrsh is located in easily identified directories.

There are also several important sources of information in the distribution:

• The INSTALL and README files provide the latest information on compiling and installing sendmail.

• The RELEASE_NOTES file lists the important features of the new release.

• The KNOWNBUGS and FAQ files explain solutions to chronic and common problems.

• The doc subdirectory contains the Sendmail Installation and Operations Guide, which is an excellent source of information for the sendmail administrator.

Of all of these important directories and files, the most important (from the perspective of this book) is the cf directory, because the cf directory contains the configuration files (and this is a book about sendmail configuration).