You cannot use Mail::Mailer in the default mode on NT as you have just discovered. You need to point the module at a mail server that can send mails on your behalf.

eval{
        my $mailer = new Mail::Mailer 'smtp', Server => $SERVER;
        
        # Send our options
        $mailer->open({
            From    =>    $SENDERALIAS . '<' . $SENDEREMAIL . '>',
            To        =>    $TO . '<' . $EMAIL . '>',
            Subject    =>    $SUBJECT
        });
        
        print $mailer $message;
    };
    
    if($@)
    {
        # Oops!
        print "$@\n";
    }
[download]

The above is an untested snippet based on the docs. I suggest you give that a try.