Recently, I wanted to change my host outgoing domain email address. Since I've been getting into the habit of using bare minimal installs, it turns out that sendmail by default does not include sendmail-cf package needed by the m4 utility to generate a sendmail .cf configuration file.
Issue:
[[email protected] mail]# m4 < sendmail.mc > sendmail.cf
m4:stdin:10: cannot open `/usr/share/sendmail-cf/m4/cf.m4': No such file or directory
Fix:
[[email protected] mail]# yum install sendmail-cf