Why another email came my phone so I can’t update

No one can move out of your account, whatever that means. where do you see this email?

If you bought the phone 2nd hand, the previous owner may not have logged out of their email. If that is the case your phone is activation locked, and will not be usable by you until they follow these instructions→Remove a device from Find Devices on iCloud.com - Apple Support, specifically the section Turn off Activation Lock on a device

I’m not sure if you have a mail message that you are concerned about, or if your iPhone is somehow now associated with a different Apple ID via Activation Lock.

If the former, delete the mail message. That mail should jot interference with an update.

If the latter, was this iPhone purchased used, or as a refurb? If it was, check with the seller.

FYI: These are user-only forums. This is not Apple Support. if you need to contact Apple Support, then contact product and tech support: 👉 Contacting Apple for support and service including international calling numbers.

Where are you see the unwanted email address? Is that email address yours? Did you use that email address as your Apple ID? Please answer all of the above questions. Thanks.

Axel F.