This article will run you through how you can view the Unlinked Enrollments inside of Salesforce.
If there is a user record passed from Northpass that contains an email address that does not match an email address included within a Salesforce contact record, it will be passed into Salesforce as an unlinked enrollment.
Select the app launcher & click the Enrollments tab
Click the drop-down arrow & select Unlinked Enrollments
Analyze the Unlinked Enrollments to see if any of them belong to contacts currently part of your Salesforce organization. To add the enrollment into your Salesforce organization, select Edit from the drop-down menu.
Add the information into a current contact or create a new contact in your Salesforce organization.