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";