When you use a workflow variable name in a string field, you can use an escape character so that the Data Integration Service displays the workflow variable name in the string instead of resolving the variable value.
Use the backslash (\) as an escape character before the ${...} syntax for workflow variable names.
For example, you have a workflow string variable named myVariable with a value of "test". You enter the following text in the body field for a Notification task:
Variable \${var:myVariable} has a value of ${var:myVariable}
When you run the workflow, the Data Integration Service displays the following string in the body field of the email: