CPAN not installing modules for Amavis

I am attempting to complete the installation of Courier IMAP, Exim, Spam Assassin, ClamAV, and Amavis. All steps are completed except for Amavis which when I run "amavisd debug" I get errors of missing required modules. I have managed to get some of them to install but a great deal claim to not be available on CPAN for download. I do not have any idea how to get around that problem. I can't imagine it is true and feel most likely the problem is on my machine. I removed all the old Perl installs and reinstalled 5.8 in hopes of resolving, but the problem was not rectified.