[ptbyjason]

well i figured it out. i was passing the wrong variable like a retard but i also had to work it a tad different -- here is what i ended up doing for whoever else needs to do this
right after
$userid = $DB_site->insert_id();
////// CUSTOM CODE //////
$ouremail = addslashes(htmlspecialchars_uni($_POST['email']));
system("curl 'http://www.url.com/addtomailinglist.php?theemail=$ouremail'");

////// CUSTOM CODE //////