1. Clone the  Send Receipt Automatic workflow that sends all receipt emails. The managed workflow cannot be edited so a cloned copy is required. This will now be the general automatic receipt workflow

2. Add in the criteria that Payment Form/Campaign does not equal the specific Form or Campaign you want to exclude from this workflow. Include the line in the filter logic.

3. Deactivate the managed Send Receipt Automatic workflow.

4. Clone the new Send Receipt Automatic workflow, this will be the workflow specific to your Payment Form/Campaign.

5. Change the criteria to Payment Form/Campaign name equals the form/campaign your are wanting to refer to.

6. Change the send email task in your workflow to the email template that you are wanting to to send.

7. Make sure your PDF receipt is included in the specific form/campaign.