function hook_mail

Prepare a message based on parameters; called from drupal_mail().

Note that hook_mail(), unlike hook_mail_alter(), is only called on the $module argument to drupal_mail(), not all modules.


$key: An identifier of the mail.

$message: An array to be filled in. Elements in this array include:

  • id: An ID to identify the mail sent. Look at module source code or drupal_mail() for possible id values.
  • to: The address or addresses the message will be sent to. The formatting of this string will be validated with the PHP e-mail validation filter.
  • subject: Subject of the e-mail to be sent. This must not contain any newline characters, or the mail may not be sent properly. drupal_mail() sets this to an empty string when the hook is invoked.
  • body: An array of lines containing the message to be sent. Drupal will format the correct line endings for you. drupal_mail() sets this to an empty array when the hook is invoked.
  • from: The address the message will be marked as being from, which is set by drupal_mail() to either a custom address or the site-wide default email address when the hook is invoked.
  • headers: Associative array containing mail headers, such as From, Sender, MIME-Version, Content-Type, etc. drupal_mail() pre-fills several headers in this array.

$params: An array of parameters supplied by the caller of drupal_mail().

Related topics

8 functions implement hook_mail()

Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.

contact_mail in drupal/modules/contact/contact.module
Implements hook_mail().
drupal_mail in drupal/includes/
Composes and optionally sends an e-mail message.
drupal_wrap_mail in drupal/includes/
Performs format=flowed soft wrapping for mail (RFC 3676).
system_mail in drupal/modules/system/system.module
Implements hook_mail().
update_mail in drupal/modules/update/update.module
Implements hook_mail().

... See full list


drupal/modules/system/system.api.php, line 2602
Hooks provided by Drupal core and the System module.


function hook_mail($key, &$message, $params) {
  $account = $params['account'];
  $context = $params['context'];
  $variables = array(
    '%site_name' => variable_get('site_name', 'Drupal'),
    '%username' => format_username($account),
  if ($context['hook'] == 'taxonomy') {
    $entity = $params['entity'];
    $vocabulary = taxonomy_vocabulary_load($entity->vid);
    $variables += array(
      '%term_name' => $entity->name,
      '%term_description' => $entity->description,
      '%term_id' => $entity->tid,
      '%vocabulary_name' => $vocabulary->name,
      '%vocabulary_description' => $vocabulary->description,
      '%vocabulary_id' => $vocabulary->vid,

  // Node-based variable translation is only available if we have a node.
  if (isset($params['node'])) {
    $node = $params['node'];
    $variables += array(
      '%uid' => $node->uid,
      '%node_url' => url('node/' . $node->nid, array(
        'absolute' => TRUE,
      '%node_type' => node_type_get_name($node),
      '%title' => $node->title,
      '%teaser' => $node->teaser,
      '%body' => $node->body,
  $subject = strtr($context['subject'], $variables);
  $body = strtr($context['message'], $variables);
  $message['subject'] .= str_replace(array(
  ), '', $subject);
  $message['body'][] = drupal_html_to_text($body);