Troubleshooting
DX Auth library might failed sending email if you didn't set the email setting well.
If that's happened, you need to create email.php in application/config/ folder, and paste following code. Edit it to fit your needs.
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
$config['protocol'] = 'smtp';
$config['smtp_host'] = 'mail.localhost.com';
$config['smtp_user'] = 'username';
$config['smtp_pass'] = 'password';
$config['smtp_port'] = '25';
For more information about this, you can consult Code Igniter email helper.