Scam

It is rare that Apple would send you an attachment unless it's a digital receipt from an Apple Store. Most of Apple's important content should be in the body of an email. This leads me to believe this is a scam email and you should avoid opening any attachments or links in it.

I suggest you read the information at Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams - Apple Support to learn more about these scam emails.

Forward the suspicious email to reportphishing@apple.com so they can prevent it happening again.

It is a phishing attempt. Do not respond. Do not divulge any personal or financial information. You can use the address below to forward the suspect email message, as an attachment to Apple.

reportphishing@apple.com

The link below has information to help identify fraudulent emails.

https://support.apple.com/en-us/HT204759