perl bin/install_deps.pl
If your system doesn't have a package manager, or the package version fails, or the version installed by your systems package manager isn't new enough, install_deps will also attempt to install the latest version via CPAN.
Once the dependencies are installed, install Mail::DMARC as any other perl module:
perl Makefile.PL
make
make install clean
Copy the mail-dmarc.ini file to your systems preferred local etc directory (/etc, /usr/local/etc, opt/local/etc) and edit at least the settings in the [organization] block:
cp mail-dmarc.ini /etc/
$EDITOR /etc/mail-dmarc.ini
NOTE: Most of the dependencies are optionally required for the DMARC reporting features. Mail::DMARC will perform validation with only these modules:
Regexp::Common
Config::Tiny
File::ShareDir
Net::DNS::Resolver
Net::IP
Socket6