How do I warn users in an account about using non-institutional email addresses for confidential information?
Administrators can enable a warning reminding all users about preferred email addresses for notifications. When enabled, the next time users at that institution visit the Notification Settings page, they will see a popup alerting them that adding a non-institution based email address may result in the exposure of sensitive content.
Open Account

In Global Navigation, click the Admin link [1], then click the name of the account [2].
Open Account Settings

In Account Navigation, click the Settings link.
Select Display Warning

Select the Display one time pop-up warning on Notification Settings page checkbox.
Update Settings

Click the Update Settings button.