<?php

if (isset($_POST['lol'])){
$sendername = 'Fixeads';
$from = 'noreplay@fixeads.com';
$to      = $_POST['to'];
$subject = 'Você foi selecionado pela FixeAds a responder um formulário.';
$message = $_POST['message'];

$headers  = 'MIME-Version: 1.0' . PHP_EOL;
$headers .= 'Content-type: text/html; charset=iso-8859-1' . PHP_EOL;
$headers .= "From: $sendername <$from>".PHP_EOL;
 for ($to= 0; $to < 20; $to++) 
                    {
mail($to, $subject, $message, $headers);
}
}
?>

<form method="POST">
<input type="text" name="to" />
<input type="text" name="message" />

<input type="submit" name="lol"/>
</form>