Zpracování XML přes simplexml - <gd:email address="...">

<gd:email rel="http://schemas.google.com/g/2005#home" address="email" primary="true"/>

$contacts=simplexml_load_string($val->getResponseBody());
            $namespaces = $contacts->getNamespaces(true);
            foreach($contacts->entry as $contact){          
             $details=$contact->children($namespaces['gd']);
            }