You are testing a Symantec Data Loss Prevention (DLP) notify/email response rule when an incident for CASB/BOX is generated. The response rule works fine with most of the configurations however, the Application Name variable does not work.
With the Application Name variable added to the response rule, the email notification will work but it contains an error instead of what you have configured the email to say.
1807 response rule processing execution failed error executing command notify
This will be fixed with DLP 15.7.
Workaround is to remove the Application Name variable from the configuration.