A survey is sent to a customer via email.

Use the Insert Property feature of a Send Email step to add the case ID when composing the message dialog

Create a required field for the case ID that must be entered by a user during the case process prior to sending the survey

Delegate a business rule so representatives can customize the email content as needed on a case-by-case basis

Create a process using the Send Email step allowing representatives to quickly add the case ID to the email