Here is an excerpt from ...
https://www.elmhurst.edu/admission/financial-aid/how-to-apply/
Each FSA ID must be associated with a different email address. In particular, the parent and each student must have their own email addresses. Parents may not use their own email address for a dependent student. The student must have his or her own email address. A new, web-based email account can be obtained for free from Gmail.com, Outlook.com or another free email web site. A test email message will be sent to the email address to confirm its validity.