Exim manualroute for system account emails?

I have my system configured to route outbound emails via smarthost. That is fine. However, for system emails (cpanelaccount@servername.com) that is sent via php mail(), I would like it to route via the server instead. I have the following router setup, but can't get it route properly The smarthost_senders_users is a domainlist smarthost_senders_users = wildlsearch;/etc/usernames
In /etc/usernames/, it's individual cpanel user names, aaa bbb ccc
dedicated_route: driver = manualroute transport = remote_smtp #domains = !+local_domains senders = smarthost_senders_users@servername..com route_list = *