Apple ID

It is a well-known scam!

If you gave any potentially damaging information to anyone, you'll need to follow up, for example, with a credit card company, Apple, Social Security, your bank, etc.

If you gave you Apple ID password to a scammer, then Change your Apple ID password https://support.apple.com/en-us/HT201355

Here is What to do after you change your Apple ID or password https://support.apple.com/en-us/HT204071

Learn about Phishing, Scams, Apple Practices,etc.

 See If you see apple.com/bill, itunes.com/bill, or an unfamiliar charge on your statement https://support.apple.com/en-us/HT201382

See Identify legitimate emails from the App Store or iTunes Store https://support.apple.com/en-us/HT201679

See How to avoid scams when using Apple Pay to send and receive money https://support.apple.com/en-us/HT208226

For scam related information from Apple including reporting scams to Apple see Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams https://support.apple.com/en-us/HT204759

Identify scams related to purported apple notifications—See what Eric Root said above.

Learn about/Increase security

See If you think your Apple ID has been compromised https://support.apple.com/en-us/HT204145

Increase the Security of your Apple ID https://support.apple.com/en-us/HT201303

iCloud security overview  https://support.apple.com/en-us/HT202303

Ways to keep your information safe on Mac https://support.apple.com/en-gb/guide/mac-help/mh11402/mac

Use Two-factor authentication for Apple ID https://support.apple.com/en-us/HT204915

Since you logged into these forums, with what I assume is the Apple ID in question, I would think the Apple ID is working fine.

Apple does not send emails warning about the Apple ID being locked. They simply warn you the next time you try it log in somewhere with it, or when you try to use it such as in the iTunes or App Stores.

The email you received is very, very likely a scam. See here: Identify legitimate emails from the App Store or iTunes Store - Apple Support

If you followed a link from the email and provided any personal details such as passwords or credit card numbers etc... I would change the password you provided, and either lock or cancel the credit card in question.

See here for more details: Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

Additional information.

Apple will always address you by your name or the name they have on file for you, not Dear Customer, Dear Client or by using your e-mail address.  The e-mail will be from @apple.com or @iTunes.com. E-mail addresses can be spoofed. You can go to Mail/View/Message/Show all Headers to see more. Apple emails won't have poor grammar/misspellings. Apple e-mails will never contain an attachment. Apple will never request personal information by email such as Social Security numbers, your Mother’s maiden name or full credit card numbers . 

The only exception to the above I have noticed is if you order something from the Apple Store (apple.com), your receipt will be addressed to Dear Apple Customer. That is a receipt for a purchase you initiated.