<?php
// Read POST request params into global vars
$to      = $_POST['to'];
$from    = $_POST['from'];
$subject = $_POST['subject'];
$message = $_POST['message'];

// Obtain file upload vars
$fileatt      = $_FILES['fileatt']['tmp_name'];
$fileatt_type = $_FILES['fileatt']['type'];
$fileatt_name = $_FILES['fileatt']['name'];

$headers = "From: $from";

if (is_uploaded_file($fileatt)) {
  // Read the file to be attached ('rb' = read binary)
  $file = fopen($fileatt,'rb');
  $data = fread($file,filesize($fileatt));
  fclose($file);

  // Generate a boundary string
  $semi_rand = md5(time());
  $mime_boundary = "==Multipart_Boundary_x{$semi_rand}x";
  
  // Add the headers for a file attachment
  $headers .= "\nMIME-Version: 1.0\n" .
              "Content-Type: multipart/mixed;\n" .
              " boundary=\"{$mime_boundary}\"";

  // Add a multipart boundary above the plain message
  $message = "This is a multi-part message in MIME format.\n\n" .
             "--{$mime_boundary}\n" .
             "Content-Type: text/plain; charset=\"iso-8859-1\"\n" .
             "Content-Transfer-Encoding: 7bit\n\n" .
             $message . "\n\n";

  // Base64 encode the file data
  $data = chunk_split(base64_encode($data));

  // Add file attachment to the message
  $message .= "--{$mime_boundary}\n" .
              "Content-Type: {$fileatt_type};\n" .
              " name=\"{$fileatt_name}\"\n" .
              //"Content-Disposition: attachment;\n" .
              //" filename=\"{$fileatt_name}\"\n" .
              "Content-Transfer-Encoding: base64\n\n" .
              $data . "\n\n" .
              "--{$mime_boundary}--\n";
}

// Send the message
$ok = @mail($to, $subject, $message, $headers);
if ($ok) {
  echo "<p>Mail sent! Yay PHP!</p>";
} else {
  echo "<p>Mail could not be sent. Sorry!</p>";
}
?>