that I will receive a $100 promo bla bla
Yes, it is a scam / phishing mail.
See the following Apple articles:
If you think your Apple ID has been compromised
If you think your Apple ID has been compromised - Apple Support
Recognize and avoid phishing messages, phony support calls, and other scams
Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support
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If you receive a suspicious email or SMS text message that looks like it's supposed to be from Apple, please email it to reportphishing@apple.com
How to report suspicious emails, messages, and calls
- If you receive a suspicious email that looks like it's supposed to be from Apple, please forward it to reportphishing@apple.com.1
- To report a suspicious SMS text message that looks like it's supposed to be from Apple, take a screenshot of the message and email the screenshot to reportphishing@apple.com.
- To report spam or other suspicious emails that you receive in your iCloud.com, me.com, or mac.com Inbox, send them to abuse@icloud.com.
- To report spam or other suspicious messages that you receive through Messages, tap Report Junk under the message. You can also block unwanted messages and calls.
- Report scam phone calls to the Federal Trade Commission (U.S. only) at reportfraud.ftc.gov or to your local law enforcement agency.
After you reported, delete the message and see -> Clear the history and cookies from Safari on your iPhone, iPad, or iPod touch
Clear the history and cookies from Safari on your iPhone, iPad, or iPod touch - Apple Support
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To keep your Apple ID account secure, see the following Apple articles:
See who has access to your device or accounts
See who has access to your iPhone or iPad – Apple Support (UK)
Delete suspicious content from your devices -> Delete suspicious content from your devices – Apple Support (UK)
Check your Apple ID device list to see where you're signed in
Check your Apple ID device list to find where you're signed in - Apple Support
- if you see devices that don't belong to you, delete from your account.
Personal Safety User Guide -> Personal Safety User Guide – Apple Support (UK)
Manage and use your Apple ID ->Manage and use your Apple ID – Apple Support (UK)
Never jailbroken your iPhone.