First decide if you wanted the notification to be On for ALL customers except the ones who say turn off. Or OFF for all customers (Selected Mode (VariableY)) except those that want it on. Click here for those settings. Note that we add a question to the closed call survey (ID109) asking people if they would like this turned on and 76% answer yes, 6% answer no.
Then decide what the default number of emails should be. Most clients set this to Call Opened, Call Dispatched and Call Closed. As there will be a survey email also that would be 4 emails your customer gets. The default can be over ridden at the customer level, so you could have one customer who only wants to be notified when the tech is dispatched and another that wants Opened/Dispatched/Closed/Cancelled/Rescheduled.