my $smtp = Net::SMTP->new('smtp.orcon.net.nz',
                           Timeout => 30,
                           Debug   => 0,  # Prevent debug info to STDOUT
                          );


$smtp->mail('no@one.com'); # Don't need to escape @ in single-quotes
$smtp->to('xxx@yyy.com');  # Fixed typo; you forgot opening quote. :)
$smtp->data();
$smtp->datasend("To: xxx\@yyy.com\n");
$smtp->datasend("\n");
$smtp->datasend("A simple test message\n");
my $res = $smtp->dataend();
$smtp->quit;

print "Operation was ", $res ? '' : 'un', "successful.\n";

##</code><code>##

use Net::SMTP;

my $smtp = Net::SMTP->new('smtp.example.com',
                           Timeout => 30,
                           Debug   => 0,  # Prevent debug info to STDOUT
                          );


$smtp->mail('someone@example.com');
$smtp->to('someone@example.com');
my $ret = $smtp->data(<<'EOM');
From: someone@example.com
To: someone@example.com
Subject: Test Message

A simple test message.
EOM

print "Operation was ", $ret ? '' : 'un', "successfull.\n";
print "(Got response: ", $smtp->message(), ")\n";

$smtp->quit;