$body ="testo da inviare";
$file="percorso_file_da_inserire";
$Mail="tua@mail";
$Mail_destinatario="mail@destinatario";
$oggetto = "Ogetto";


//---- messaggio con contenuto di diversi tipi (testo / allegati)


$headers = "From:$Mail\r\n";
$headers .= "Reply-To:$Mail\r\n" ;
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: multipart/mixed;\r\n\tboundary=\"nextpart\"\r\n";
//---- testo messaggio
$headers .= "--nextpart\r\n";
$headers .= "Content-Type: text/html;\r\n\tcharset=\"iso-8859-1\"\r\n";
$headers .= "Content-Transfer-Encoding: 8bit\r\n";



//---- allegato messaggio
$message .= "\r\n--nextpart\r\n";
$message .= "Content-Type: application/pdf;\r\n\tname=\"$file\"\r\n";
$message .= "Content-Transfer-Encoding: base64\r\n";
$message .= "Content-Disposition: attachment;\r\n\tfilename=\"$file\"\r\n\r\n";
$stringpdf = join ('', file($file));
$message .= chunk_split(base64_encode($stringpdf));
$message .= "\r\n--nextpart--";



//---- spedizione mail



mail($Mail_destinatario,$oggetto,$message,$headers );