Codice PHP:
<?php

// RENDIAMO LO SCRIPT COMPATIBILE CON LE VERSIONI DI PHP < 4.1.0
if(!isset($_POST)) $_POST $HTTP_POST_VARS;
if(!isset(
$_FILES)) $_FILES $HTTP_POST_FILES;

// RIPULIAMO I VARI CAMPI DEL MODULO
$Destinatario trim($_POST["Destinatario"]);
$Soggetto trim(stripslashes($_POST["Soggetto"]));
$Contenuto trim(stripslashes($_POST["Contenuto"]));

// ASSEGNIAMO A VARIABILI PIU' LEGGIBILI, LE PROPRIETA' DELL'ALLEGATO
$attach $_FILES["allegato"]["tmp_name"];
$file_name $_FILES["allegato"]["name"];
$file_type $_FILES["allegato"]["type"];
$file_size $_FILES["allegato"]["size"];

// DELIMITATORE
$boundary md5(uniqid(microtime()));

// APRIAMO L'ALLEGATO PER LEGGERLO E CODIFICARLO
$file = @fopen($attach"r");
$contents = @fread($file$file_size);
$encoded_attach chunk_split(base64_encode($contents));
@
fclose($file);

// INTESTAZIONI DELLA MAIL
$mail_headers .= "MIME-version: 1.0\n";
$mail_headers .= "Content-type: multipart/mixed; boundary=\"$boundary\"";
$mail_headers .= "X-attachments: $file_name\n";

// COSTRUIAMO IL CORPO DELLA MAIL
$mail_body "--$boundary\n";
$mail_body .= "Content-Type: text/plain; charset=us-ascii\n";
$mail_body .= "Content-Transfer-Encoding: 7bit\n\n";
$mail_body .= "$Contenuto\n\n";
$mail_body .= "--$boundary\n";
$mail_body .= "Content-type: $file_type; name=\"$file_name\"\n";
$mail_body .= "Content-Transfer-Encoding: base64\n";
$mail_body .= "$encoded_attach\n";
$mail_body .= "--$boundary--\n";

// INVIO DELLA MAIL
if(@mail($Destinatario$Soggetto$mail_body$mail_headers)) { // SE L'INVIO E' ANDATO A BUON FINE...

echo "La mail è stata inoltrata con successo.";

} else {
// ALTRIMENTI...

echo "Si sono verificati dei problemi nell'invio della mail.";

}

?>

E' pari pari quello di gm