sendmail, 4th Edition

Configure with m4

The process of building a sendmail configuration file begins by creating a file of m4 statements. Traditionally, the suffix for such files is .mc. The cf/cf directory contains examples of many .mc files. Of special interest are those that begin with generic, for these can serve as boilerplates in developing your own .mc files:

generic-bsd4.4.mc    generic-mpeix.mc        generic-sunos4.1.mc
generic-hpux10.mc    generic-nextstep3.3.mc  generic-ultrix4.mc
generic-hpux9.mc     generic-osf1.mc
generic-linux.mc     generic-solaris.mc

All .mc files require specific minimal statements. For a SunOS 4.1.4 site on the Internet, for example, the following are minimal:

OSTYPE(sunos4.1)dnl         ← see §17.2.2.1 on page 590
MAILER(local)dnl            ← see §17.2.2.2 on page 590
MAILER(smtp)dnl             ← see §17.2.2.2 on page 590

To build a configuration file from these statements, you would place them into a file—say, localsun.mc—and then run the following command:

% ./Build localsun.cf
Using M4=/usr/5bin/m4
rm -f localsun.cf
/usr/5bin/m4 ../m4/cf.m4 localsun.mc > localsun.cf || ( rm -f localsun.cf && exit 1 )
chmod 444 localsun.cf

Here, you run the Build^[235] script found in the cf/cf directory. You pass it the name of your mc file with the “.mc” suffix changed to a “.cf” suffix. The Build script uses m4 to expand your mc file into a full-fledged configuration file.

Another way to build a configuration file is by running m4 by hand:

% m4  ../m4/cf.m4 localsun.mc >  sendmail.cf

Here, the ../m4/cf.m4 tells m4 where to look for its ...