Execute this command on a command line:

sudo perl -MCPAN -e shell

It will install CPAN if not already installed. Then it will take you to CPAN prompt.

On CPAN prompt, execute this command to install Perl module:

CPAN> install module name

For example:

CPAN> install Net::SMTP::TLS

CPAN is “Comprehensive Perl Archive Network” which is a repository of several useful Perl modules.