sendmail is a complex topicmuch too complex to be truly covered by a single chapter. This chapter should get you started and will help you configure a simple server. However, if you have a complex configuration or you want to explore advanced features, you will need more information. Here are some sources to start you on your quest for knowledge.
The sendmail distribution is delivered with some excellent README files. The README file in the top-level directory created when the distribution is installed is the place to start. It contains a list of other informational files, such as sendmail/README and cf/README, that provides essential information. (The cf/README file, which covers the sendmail configuration language, is also available on the Web at http://www.sendmail.org/m4/readmel.)
The sendmail Installation and Operations Guide is an excellent source of information. It is also delivered with the sendmail source code distribution, and can be found in doc/op/op.me or doc/op/op.ps, depending on your preferred format.
The sendmail web site provides several excellent papers and online documents. The Compiling Sendmail documentation, available at http://www.sendmail.org/compilingl, is an excellent example.
The sendmail site provides a list of available sendmail books at http://www.sendmail.org/booksl.
Formal sendmail training is available. Some training classes are listed at http://www.sendmail.org/classesl.
Using these resources, you should be able to find out more about sendmail than you will ever need to know. Go exploring!