foreach ($message->rfc822_header->mlist as $cmd => $actions) {
/* I don't know this action... skip it */
- /* array_key_exists works only in >= 4.1 */
- if ( !in_array($cmd, array_keys($fieldsdescr)) ) {
+ if ( ( function_exists('array_key_exists') && /* PHP >= 4.1 */
+ !array_key_exists($cmd, $fieldsdescr) ) ||
+ !key_exists($cmd, $fieldsdescr) /* PHP == 4.0.6 */
+ ) {
continue;
}