Alerting Module - Custom Subject for Job Alert Issue

I am implementing alerting functionality through the Alerting Module. I am trying to create custom subjects that include the job that failed.

According to the admin guide you can do this through an email gateway.

Example

Creating an email gateway for masalan.com

1. Navigate to Alerting > Email Gateways.

2. Choose New Email Alert Gateway from the context-menu.

3. Fill in the fields Name, fill *@masalan.com into the Address Pattern and 99 into Processing Order.

4. On the Headers tab, choose Add and fill From into the Name field and prd-operators@masalan.com

into the Value field.

5. On the Headers tab, choose Add and fill subject into the Name field and prd-Job ${topLevelJobId}

failed: ${subject}

After completing this setup and running a test I am getting the following output on the email subject -

"prd-Job ${topLevelJobId} failed: Alert: Acknowledge"

Any Ideas?

Thanks