Campaign administrator "Send test email" function not working

In HCM Communicate, when I am logged in as the campaign administrator, and navigate to Setup & Maintenance > HCM Communicate > Manage Email Templates, I am trying to use the Send Test Email function (as the campaign admin) to see what the template looks like as the end user. However, it is saying the email was sent but I receive nothing in my inbox. I let it sit overnight thinking it could be delayed but it never came through. This is happening in my clients testing environment. When I tried the same action in a different environment, I was