event_stub — event sender service plugin
event_proxy connects to the event(8gx) daemon and sets itself up so as to be able to send notifications.
event_proxy installs three service functions, "broadcast_event", "broadcast_select" and "broadcast_unselect", though the latter two are just convenience functions for broadcast_event. broadcast_event is for synchronously sending a notification into the event distribution system. Arbitrary notifications and commands can be sent this way. The return value is ignored.
In practice, midb(8gx), imap(8gx) and pop3(8gx) issue FOLDER-TOUCH notifications. Only imap(8gx) issues MESSAGE-FLAG notifications.