PHP Codeigniter: Is there an elegant way to to get the SMTP return code upon a mail failure

I dont think there is a build in mechanism for this in CodeIgniter. What you could do is extend the CI email class and add a function to expose the protected _debug_msg array.

If you look at the source of email class you will see that print_debugger() function is converting _debug_msg array into string. So if _debug_msg has what you are looking for then you wouldn't have to parse any string.

class MY_Email extends CI_Email {    public function __construct()    {        parent::__construct();    }    public get_msg()    {        if (count($this->_debug_msg) > 0)        {            return $this->_debug_msg;        }        else        {            return FALSE;        }    }}

Refer the following link on how to extend CI libshttp://codeigniter.com/user_guide/general/creating_libraries.html

If you're sending emails using sendmail you may not be able to get the SMTP return codes until later.

The way to get bounces (I'm guessing?) is by adding a Return-Path to your outgoing emails and choose an email inbox that's manned by procmail, so that you can pipe the feedback emails back into PHP to parse it.

Let me know if you need more details on the above.