Have a look in the CQ documentation, maybe there you will find more detailed information about this issue:
Other thing is that in order to have a detailed control over all workflow events sent by email it is not possible to use default notifications from CQ.
There is the possibility to define a workflow event listener inside a bundle in which depending on your requirements is possible:
- decide if to process or not the event
- decide if an event has to be processed based on the payload
- decide to send notifications based also on the initiator
Of course in this case there is needed some custom code to develop on your side.