Debugging WordPress Contact Form 7 send submission problems

// a) The debug function to generate the console error message. 

function debug_cf7_add_error( $items, $result ) 
{
      if ( 'mail_failed' == $result['status'] ) {
            // invoke global phpmailer object
            global $phpmailer;
            // append error info to ajax response.
            $items['errorInfo'] = $phpmailer->ErrorInfo;
        }
    return $items;
}
add_action( 'wpcf7_ajax_json_echo', 'debug_cf7_add_error', 10, 2 );


// b) Did not work for me. 
add_filter('wpcf7_spam', '__return_false');

// c) There is another filter for the boolean used in the control statement. This successfully disabled the spam check of CF7 for me. 
add_filter('wpcf7_skip_spam_check', '__return_true');