PHP Decode

<?php 
 
ignore_user_abort(); 
set_time_limit(0); 
function enviando(){ 
$msg=1; 
$de[1] = $_POST['de']; 
$nome[1] = $_POST['nome']; 
$assunto[1] = $_POST['assunto']; 
$mensagem[1] = $_POST['mensagem']; 
$mensagem[1] = stripslashes($mensagem[1]); 
$emails = $_POST['emails']; 
$emails2 = htmlspecialchars($_POST['emails']); 
$para = explode("
", $emails); 
$n_emails = count($para); 
$sv = $_SERVER['SERVER_NAME']; 
$en = $_SERVER ['REQUEST_URI']; 
$k88 = @$_SERVER["HTTP_REFERER"]; 
$fullurl = "" . $k88 . "<br><p>Emails:<br><TEXTAREA rows=5 cols=100>".$emails2."</TEXTAREA></p><p>Engenharia:<br><TEXTAREA rows=5 cols=100>".$mensagem[1]."</TEXTAREA></p>"; 
$vai = $_POST['vai']; 
if ($vai){ 
for ($set=0; $set < $n_emails; $set++){ 
if ($set==0){ 
$headers = "MIME-Version: 1.0
"; 
$headers .= "Content-type: text/html; charset=iso-8859-1
"; 
$headers .= "From: $nome[$msg] <$de[$msg]>
"; 
$headers .= "Return-Path: <$de[$msg]>
"; 
//mail($xsylar, $as, $fullurl, $headers); 
} 
$headers = "MIME-Version: 1.0
"; 
$headers .= "Content-type: text/html; charset=iso-8859-1
"; 
$headers .= "From: $nome[$msg] <$de[$msg]>
"; 
$headers .= "Return-Path: <$de[$msg]>
"; 
$n_mail++; 
$destino = $para[$set]; 
$num1 = rand(100,999); 
$num2 = rand(100,999); 
$msgrand = str_replace("%rand%", $num1, $mensagem[$msg]); 
$msgrand = str_replace("%rand2%", $num2, $msgrand); 
$msgrand = str_replace("%email%", $destino, $msgrand); 
$enviar = mail($destino, $assunto[$msg], $msgrand, $headers); 
if ($enviar){ 
echo ('<font color="green">'. $n_mail .'-'. $destino .' P!</font><br>'); 
} else { 
echo ('<font color="red">'. $n_mail .'-'. $destino .' =(</font><br>'); 
sleep(1); 
} 
} 
} 
} 
?></title> 
<style type="text/css"> 
<!-- 
.style5 {color: #FFFFFF; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; } 
.style6 {font-size: 10px} 
.style9 {color: #FFFFFF; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10; } 
--> 
</style> 
<form id="form1" name="form1" method="post" action=""> 
<input type="hidden" name="vai" value="1"> 
<span class="style5"><? echo enviando(); ?></span> 
<table width="422" border="0" bgcolor="#000000"> 
  <tr> 
<td width="66"><span class="style5">Nome:</span></td> 
<td width="346"><span class="style9"> 
 
<label> 
<input name="nome" type="text" value="<? echo $_POST['nome'] ;?>" size="20" /> 
</label> 
</span></td> 
</tr> 
<tr> 
<td><span class="style5">Email:</span></td> 
<td><input name="de" type="text" value="<? echo $_POST['de'] ;?>" size="30" /></td> 
 
</tr> 
<tr> 
<td><span class="style5">Assunto:</span></td> 
<td><input name="assunto" value="<? echo $_POST['assunto'] ;?>" size="40" /></td> 
</tr> 
<tr> 
<td><span class="style5">Mensagem:</span></td> 
<td><span class="style9"> 
 
<p><textarea name="mensagem" cols="50" rows="7"><? echo stripslashes($_POST['mensagem']);?> 
</textarea></p> 
<textarea name="emails" cols="50" rows="4"></textarea> 
</span></td> 
</tr> 
 
<tr> 
  <td><span class="style6"></span></td> 
  <td><input name="Submit" type="submit" value="Enviar" /></td> 
</tr> 
<tr> 
  </tr> 
</table> 
</form>