public static function check_server_connectivity($cache_timeout = 86400) {
    
    $debug = array();
    $debug[ 'PHP_VERSION' ]         = PHP_VERSION;
    $debug[ 'WORDPRESS_VERSION' ]   = $GLOBALS['wp_version'];
    $debug[ 'AKISMET_VERSION' ]     = AKISMET_VERSION;
    $debug[ 'AKISMET__PLUGIN_DIR' ] = AKISMET__PLUGIN_DIR;
    $debug[ 'SITE_URL' ]            = site_url();
    $debug[ 'HOME_URL' ]            = home_url();
    
    $servers = get_option('akismet_available_servers');
    if ( (time() - get_option('akismet_connectivity_time') < $cache_timeout) && $servers !== false ) {
      $servers = self::check_server_ip_connectivity();
      update_option('akismet_available_servers', $servers);
      update_option('akismet_connectivity_time', time());
    }

    if ( wp_http_supports( array( 'ssl' ) ) ) {
      $response = wp_remote_get( 'https://rest.akismet.com/1.1/test' );
    }
    else {
      $response = wp_remote_get( 'http://rest.akismet.com/1.1/test' );
    }

    $debug[ 'gethostbynamel' ]  = function_exists('gethostbynamel') ? 'exists' : 'not here';
    $debug[ 'Servers' ]         = $servers;
    $debug[ 'Test Connection' ] = $response;
    
    Akismet::log( $debug );
    
    if ( $response && 'connected' == wp_remote_retrieve_body( $response ) )
      return true;
    
    return false;
  }