That email is a scam/phishing email. The scammer is attempting for you to click on the link and that will take you to a fake site which will resemble like Apple's website. You will then be asked to input your Apple ID and password and the scammer will capture those credentials. I hope that you did not input your credentials.
Furthermore, that is not an iPhone case that the email is referring to. It is referring to a "case" meaning a record.
All about scams and phishing -
Beware of ➔ Phishing & Other Suspicious Emails
Know how to ➔ Identify legitimate emails from the App Store or iTunes Store
Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams ➔ Use these tips to avoid scams and learn what to do if you think your Apple ID has been compromised.
Axel F.