1 email_example.module email_example_mail($key, &$message, $params)

Implements hook_mail().

This hook defines a list of possible e-mail templates that this module can send. Each e-mail is given a unique identifier, or 'key'.

$message comes in with some standard properties already set: 'to' address, 'from' address, and a set of default 'headers' from backdrop_mail(). The goal of hook_mail() is to set the message's 'subject' and 'body' properties, as well as make any adjustments to the headers that are necessary.

The $params argument is an array which can hold any additional data required to build the mail subject and body; for example, user-entered form data, or some context information as to where the mail request came from.

Note that hook_mail() is not actually a hook. It is only called for a single module, the module named in the first argument of backdrop_mail(). So it's a callback of a type, but not a hook.

Related topics


modules/examples/email_example/email_example.module, line 40
Example of how to use Backdrop's mail API.


function email_example_mail($key, &$message, $params) {
  global $user;

  // Each message is associated with a language, which may or may not be the
  // current user's selected language, depending on the type of e-mail being
  // sent. This $options array is used later in the t() calls for subject
  // and body to ensure the proper translation takes effect.
  $options = array(
    'langcode' => $message['language']->langcode,

  switch ($key) {
    // Send a simple message from the contact form.
    case 'contact_message':
      $message['subject'] = t('E-mail sent from @site-name', array('@site-name' => config_get('system.core', 'site_name')), $options);
      // Note that the message body is an array, not a string.
      $message['body'][] = t('@name sent you the following message:', array('@name' => $user->name), $options);
      // Because this is just user-entered text, we do not need to translate it.
      // Since user-entered text may have unintentional HTML entities in it like
      // '<' or '>', we need to make sure these entities are properly escaped,
      // as the body will later be transformed from HTML to text, meaning
      // that a normal use of '<' will result in truncation of the message.
      $message['body'][] = check_plain($params['message']);