A Preferred Email is a secondary email field available to users who authenticate to a digital workplace using SSO. The Preferred Email address is where all workplace notifications are sent. Unless changed, a user's Preferred Email will be the same as their account email. Users can change their preferred email from the Email Settings page of their Personal Profile.
Administrators can view users' Preferred Emails by exporting the workplace's member list. The resulting CSV file contains a column for Preferred Email.