#!/usr/bin/perl -wT
use strict;
use CGI;
use Email::Valid;

my $cgi           = CGI-new();
my $email         = $cgi->param( 'visitors_email_address' );
my $password      = $cgi->param( 'visitor_password' );
my $valid_address = Email::Valid->address( $e-mail );

if ( $valid_address ) {
    # Address is valid, do stuff here
    # This DOES NOT mean that the address is real
} else {
    # Address is invalid.
}