The sendmail.cf file for sendmail+IDA is not edited directly, but is generated from an m4 configuration file provided by the local system administrator. In the following, we will refer to it as sendmail.m4.
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.