How do I close a request via email in Service Desk Plus

How do I close a request via email in Service Desk Plus

We are in the process of evaluating Service Desk Plus (SDP)

I've configured SDP to Send and Receive email.  SDP is able to create and route new request via email.
It will send an email to a tech when they have been assigned a request.

I understand from the documentation that a Tech is supposed to be able to close a request via email.
I've not been able to do that.
I've included @SDP@ in the subject line and have tried

@@Operation = CloseRequest@@ as well as @@Status = Closed@@ but the status remains the same.  I've also tried the same text without the spaces around the '='.

Could someone please instruct me on how to close a request via email?















                  New to ADSelfService Plus?