To install these programs, proceed as follows,
 - Install and compile qmail. The qmail source should be in a directory
   named qmail-1.03; such as /usr/local/src/qmail-1.03.
 - Make sure that you've put this code in a directory 'Parallel' to qmail.
   So if you have qmail in /usr/local/src/qmail-1.03, put this code in
   /usr/local/src/qmail-hashdir, for example.
 - Adjust the source according to your requirements. In particular, check
   that the settings in Makefile ($INSTALLDIR, $HASH_USER) and in
   hash_core.h (particularly maildirs_basedir) match your expectations.
 - In this directory, type,
     make all
     make install
   which will install the executables to $INSTALLDIR.
 - You'll then need to work these programs into your qmail installation.
   For details of this, see all the USAGE.xxx files.
 - You should also review the NOTES file.