When you account is created the default contact is created. Once your account has been validated you will be able to send email messages to this contact. One of the drawbacks to this default contact is that if it is hosted on the mail server that is being monitored that there is a chance that an alert is missed when your mail server is down. 

Our best practice suggestion is to create a secondary email notification address on a third party for notifcations. 

Follow this guide to setting up a new contact and notification - http://support.mailflowmonitoring.com/solution/articles/5000810322-create-new-contact