postoffice-1.0.x-dev/extensions/postoffice_compat/tests/modules/postoffice_compat_fallback_test/postoffice_compat_fallback_test.module

<?php

/**
 * @file
 * Primary module hooks for Postoffice Compat Fallback Test module.
 */

/**
 * Implements hook_mail().
 */
function postoffice_compat_fallback_test_mail($key, &$message, $params) {
  $message['subject'] = $params['subject'];
  $message['body'] = $params['body'];
}