I'm trying to send email notifications when someone enters a Case Comment. Since there doesn't appear to be a way to do this via configuration, I have create a Visual Flow that will create a Case Comment Notification record, which will in turn send an email. That works just fine.
However, I need to include the Case Email Thread so that when the requester replies to the notification, it is tracked back to the case. But, when I try to find this field on the Case object in Visual Flow, it doesn't appear.
How can I obtain the Email Thread in Visual Flow so that I can include it in my email?