The rescue email address is dedicated to your security and allows Apple to get
in touch if any account questions come up, such as the need to reset your
password or change your security questions. As promised, Apple will never send
any announcements or marketing messages to this address.
When using Apple
products and services, you’ll still sign in with your primary email address as
your Apple ID.
It’s about protecting your identity.
Just so
you know, Apple sends out an email whenever someone adds or changes a rescue
email address associated with an existing Apple ID. If you received this email
in error, don’t worry. It’s likely someone just mistyped their own email address
when creating a new Apple ID.
If you have questions or need help, visit
the Apple ID Support
site.