index.php

<?php
  header('Content-type: text/plain; charset=UTF-8');

  $config = array(
    'emails' => ['ener@mailinator.com'],
    'subject' => "Nowe zgloszenie Energia",
    'fields' => array (
      'name' => array ('label' => 'Imię i nazwisko'),
      'email' => array ('label' => 'Adres e-mail'),
      'phone' => array ('label' => 'Telefon'),
      'street' => array ('label' => 'Ulica'),
      'city' => array ('label' => 'Miasto'),
      'message' => array ('label' => 'Wiadomość', 'newline' => true),
    ),
  );
  
  $message = 'Nowe zgłoszenie' . "\n\n";
  $valid = true;
  $mq = get_magic_quotes_gpc();
  foreach ($config['fields'] as $key => $field) {
    if (empty($_POST[$key])) {
      $valid = false;
      break;
    }
    
    $value = $_POST[$key];
    if ($mq) {
      $value = stripslashes($value);
    }
    
    $newline = isset($field['newline']) ? "\n" : "";
     
    $message .= sprintf("%s: %s%s\n", $field['label'], $newline, $value);    
  }
  
  if ($valid) {
    foreach ($config['emails'] as $recipient) {
      mail($recipient, $config['subject'], $message, 'Content-type: text/plain; charset=UTF-8');
    }
  }
  
  $target = isset($_POST['target']) ? $_POST['target'] : null;
  $target = ($mq && $target) ? stripslashes($target) : $target;
  
  if ($target) {
    header('Location: ' . $target . ((false === strpos($target, '?'))?'?':'&') . 'success=' . ((int)$valid));
  }
?>