Red Hat, Inc. distributes sendmail in RPM format. If you're looking for the source code it is available from http://www.sendmail.org or you can get the version Red Hat provides by installing sendmail-8.9.3-15.src.rpm (8.9.3-20 for Zoot) from the second CD-ROM in your distribution. Run rpm -i sendmail-8.9.3-15.src.rpm and it will be installed. For those who are brand new to Red Hat Linux or have never worked with RPM before this does not install a binary package on your system the way xxxxxxx.$arch.rpm files do. It actually installs the source code and any required patches into /usr/src/redhat/SOURCES/, as well as a file called sendmail.spec into /usr/src/redhat/SPECS/. The spec file is very important as it is the instruction set used by RPM to build the binary RPMs. Once you have done the install you can look at the spec file and get some idea of what Red Hat has included for you.
First of all the sendmail source RPM builds 3 binary RPMs when compiled. They are:
sendmail-8.9.3-15.i386.rpm <--- this is the binary RPM which contains sendmail itself
sendmail-cf-8.9.3-15.i386.rpm <--- this RPM is required if you plan to reconfigure sendmail using m4
sendmail-doc-8.9.3-15.i386.rpm <--- this RPM contains all of the documentation for sendmail including the sendmail FAQ
To build the binary RPMs execute the following command:
rpm -bb /usr/src/redhat/SPECS/sendmail.spec
When the build process is complete your new binaries will be located in /usr/src/redhat/RPMS/i386/.
You can install them by executing rpm -U /usr/src/redhat/RPMS/i386/sendmail*.