You can opt for receiving a confirmation email before triggering any workflow for the chosen user list. Just 3 days before the first stage of the workflow automation trigger date, you will receive an email containing the user list. If you do not wish to trigger campaign for particular contacts, you may remove them from the list by clicking opt-out.

Steps to receive email notification

1. Navigate to Engagement>Automations
2. Select the automation segment to Create the workflow
3. After designing the workflow, while reviewing the workflow information
4. Click on Agent Email Notification as shown below, then click Start.