This file contains a few definitions and otherwise merely points to the tables where the real work gets done. In general, it is only necessary to specify:
There are a large variety of parameters that can be defined to establish the behavior of the local site or to override compiled-in configuration items. These configuration options are identified in the file ida/cf/OPTIONS in the source directory.
A sendmail.m4 file for a minimal configuration (UUCP or SMTP with all non-local mail being relayed to a directly connected smart-host) can be as short as 10 or 15 lines excluding comments.