Unable to subscribe to lists

Hi I'm trying to subscribe to internals mail list by following instructions here: http://php.net/support.php and here: https://secure.php.net/mailing-lists.php but to avail. For example, I check the 'Normal' radio for the internals list and enter my email address and click 'Subscribe', the page reloads but there's no acknowledgement that I was subscribed and I receive no email. I also tried following instructions at the bottom of the mailing lists page, sending an email to php-internals-help@lists.php.net but I get a 550 error back from gmail: "550 php-internals-subscribe@lists.php.net is not a valid address". Is there any other way I can subscribe at all? Thanks Matt