It’s easy to think that an iOS backup would include all the personal data stored on your iPhone or iPad. But Apple explains in a support page that some things aren’t copied off your phone, because they’re stored elsewhere. This includes “data stored in other cloud services, like Gmail and Exchange mail.”
What if you download messages from an email account to your iOS device and they’re deleted from the server? Those emails are gone for good when your iPhone or iPad is restored from backup or dies. Apple doesn’t mention this in the support note or elsewhere, even though it can affect people who store certain messages locally on their devices instead of synced with a mail server.
