Send list of node title and body via email to users
Hope this will help you create a module with hook_cron

    function mymodule_cron()  {

      $time_fetch=time();
    $result = db_query("SELECT node.title AS node_title, node.nid AS nid, node.created AS node_created, 'node' AS field_data_body_node_entity_type
    FROM 
    {node} node
    LEFT JOIN {node_revision} node_revision ON node.vid = node_revision.vid
    LEFT JOIN {node} node_node_revision ON node_revision.nid = node_node_revision.nid
    WHERE (( (node.status = '1') AND (node.type IN  ('question')) AND (node.created BETWEEN $time_fetch+0 AND $time_fetch -604800) ))
    ORDER BY node_created DESC")-&gt;fetchAll(PDO::FETCH_ASSOC);
            //WHERE date BETWEEN DATE(NOW( ) + INTERVAL 7 DAY ))-&gt;fetchAll(PDO::FETCH_ASSOC);
        $all_user = db_query("SELECT users.mail AS users_mail, users.uid AS uid, users.created AS users_created
    FROM 
    {users} users
    WHERE (( (users.status &lt;&gt; '0') ))
    ORDER BY users_created DESC")-&gt;fetchAll(PDO::FETCH_ASSOC);   

        foreach ($result as $mail_data) 
        {
            foreach ($all_user as $user_mail) {
            //dpm($mail_data);
            //dpm($user_mail);
//here i think you can use the drupal_mail function
            //$message = drupal_mail('mymodule', 'message_key', $to, user_preferred_language($user), array('body' =&gt; $body, 'subject' =&gt; $subject, $from, TRUE));

        }
        }
        }


the drupal mail api is here drupal_mail