Advanced sendmail configuration

Mail and Messaging Guide
Chapter 5, sendmail administration

Most sendmail configuration is accomplished by editing the configuration file, /usr/lib/sendmail.cf. The syntax of this file is designed to be reasonably easy to parse, because this is done every time sendmail starts up. As a result, the configuration file is not particularly easy for a human to read or write.

The configuration file has three major purposes:

setting up the environment for sendmail
rewriting addresses in the message
mapping addresses into the set of instructions that will deliver the message

For further details see ``Purpose of the configuration file''.

This section provides an overview of the standard configuration file built with the mkdev cf script, provides the specifications for configuration file lines, and describes building a configuration file from scratch.