If you use a school email address with your Apple ID, the organization that owns your email address might reclaim it after you’ve left so they can assign it to someone else. When this happens, you'll receive email and device notifications from Apple instructing you to choose a new email address for your Apple ID within 30 days.
Updating the email address for your Apple ID only changes the email address you use when you sign in to your Apple ID. The data and purchases associated with your account remain with your account and aren't affected. The password for your Apple ID won’t change, unless you decide to change it.
You'll receive frequent email and device notifications until your Apple ID is updated.
Change your Apple ID email address
You can update your Apple ID email address with any third-party email address, or you can create an @icloud.com email address. If you create an @icloud.com email address, you might need to wait 30 days before you can use your @icloud.com email address as your primary Apple ID.
Learn how to change your Apple ID email address.
About the data associated with your Apple ID
Changing your email address only changes the Apple ID that other people see when sharing with you, and the email address Apple uses to contact you regarding your account. The organization reclaiming your email address won't have access to your data, and your data remains with your Apple ID whether or not you change the email address associated with your account.
This data includes content you might store in iCloud, like photos, videos, and documents, as well as any App Store, iTunes Store, and Apple Books purchases, or Apple Music subscription. Sign in with your updated Apple ID email address to continue using iCloud, the App Store, iTunes Store, Apple Books, Apple Pay, iMessage, FaceTime, Find My iPhone, and more.
If you don’t update your Apple ID email address
If you don't choose a new email address for your Apple ID within 30 days of the first notification from Apple, services associated with your Apple ID like iMessage and FaceTime are inactive until you change your Apple ID email address.
Update your Apple ID email address after 60 days
If you don't update your Apple ID within 60 days of the first notification from Apple, your Apple ID changes to a temporary username that includes @temporary.appleid.com. For example, firstname.lastname@example.org changes to email@example.com.
To update your Apple ID after 60 days of the first notification from Apple, sign in with your temporary Apple ID when you change your Apple ID email address.