On most modern systems, Perl will be pre-installed. If not, it can be downloaded from many locations including www.perl.org, and binary distributions are also available for platforms such as Solaris.
MailScanner has been tested with Perl 5.8 and everything works very well.
The following Perl modules are needed by MailScanner:
The additional modules are all available from your nearest CPAN mirror, or from their respective authors' sites which are linked in the list above.
Install the modules listed above in the order they are given, ensuring you do the "make test" step for each one to check they work. The steps required to install each module are contained in their accompanying documentation.
If you are having trouble installing them, check out my hints and tips page.
In order to apply the patches to MIME-tools, you will have to download the source (follow the MIME-tools link above), unpack it, apply the 4 patches and then build and install the module by hand. If you don't know how to apply patches, read "man patch". If you don't know how to install a Perl module, then read the "Installing" file in the MIME-tools package you are about to download.
When you do the "make test" step for MIME-tools, do not worry if the "spamd" tests fail, as MailScanner does not use "spamd" anyway.