I switched from version 1.7.X to 1.9.4 and this feature seems to be changed.
In a nutshell, as an Admin of the booking system, I am free to change the status of the appointment from Confirmed to Paid, for example.
I need that the system sends an email to the customer only once, when the appointment is requested from the front end.
Currently the customer receives an email every time I change status of his appointment.
Is there a way to disable it?