Case Email Response Notification

[joy11]

I'm using the Case entity and creating automatic cases from email. My users email the client and then when the client responds it is added to the ticket in the stream and linked on the side under emails, but there is no notification sent out to the user that a reply has come in. It's added to the stream and I've been unable to create any kind of trigger to send out a notification. I have other workflows sending emails when a case is modified or closed, but they do not check stream data. I also have the "Notifications about updates in Stream for internal users" checked for Cases in the Notifications section. (On version 4.3.1) That seems to only send notifications when a user adds something to the stream and not for the email reply that is added. My users do not receive the support emails to their inbox, so they have to go into each ticket to check for a reply.

Am I overlooking where to turn this feature on or is this something I'll need to create? If I have to create it are there files I can look at for examples?