The installation for this program to integrate with sendmail is documented in the "standard" INSTALL notes, currently at:

http://www.pccc.com/downloads/sendmail/current-8.12.X/untarred/INSTALL

However, initially, you should be able to get things running by creating blank default databases and running poprelayd-KAM.pl -d

  makemap hash /etc/mail/popauth.db < /dev/null
  makemap hash /etc/mail/rcpt_flood.db < /dev/null
  chmod 644 /etc/mail/popauth.db /etc/mail/rcpt_flood.db

You will also need to install the Perl Module IPTables-IPv4 mirrored here.  

ERRORS: If you get an odd error like mkbookstrap doesn't exist, edit the Makefile.PL on line 61 and change PERLRUN to PERL

  Running Mkbootstrap for IPTables::IPv6 ()
  /bin/sh: -MExtUtils::Mkbootstrap: command not found
  make: *** [IPv6.bs] Error 127
 
Also, if you are running kernel 2.6.22, the headers have changed and patch might be needed.

Finally, if you cannot make test, see the information below:

make test throws errors such as:

Use of uninitialized value in <HANDLE> at /usr/src/IPTables-IPv4-0.98/blib/lib/IPTables/IPv4/Toplevel.pm line 50.
readline() on unopened filehandle at /usr/src/IPTables-IPv4-0.98/blib/lib/IPTables/IPv4/Toplevel.pm line 50.

This is caused by trying to read /proc/net/ip_tables_names, etc.

https://rt.cpan.org/Ticket/Display.html?id=48658

#48658: Make test fails if no iptables rules have been defined prior 

Creating blank rules with the following commands resolved my issue and allowed for a make test.

#FLUSH EVERYTHING
/sbin/iptables -t filter -F INPUT
/sbin/iptables -t filter -F OUTPUT
/sbin/iptables -t filter -F FORWARD
/sbin/iptables -t nat -F PREROUTING
/sbin/iptables -t nat -F OUTPUT
/sbin/iptables -t nat -F POSTROUTING
/sbin/iptables -t mangle -F PREROUTING
/sbin/iptables -t mangle -F OUTPUT

#DEFAULT RULES
/sbin/iptables -t filter -P INPUT ACCEPT
/sbin/iptables -t filter -P OUTPUT ACCEPT
/sbin/iptables -t filter -P FORWARD DROP