I receive several emails daily saying I haven't paid for cloud storage and I'll be suspended if I don't pay soon using link in email. I think I paid but want to be sure. Can you help?

Know it here --> If your payment method is declined in the App Store or iTunes ...

Check the following

1. The payment method that you are adding is of the same country as that of App Store Country on your iPhone
2. You have a valid payment plan debit/credit card from an authorised bank from the same country
3. Payment methods that you can use with your Apple ID - Apple Support
4. Learn more about family purchases and payments.
5. Please check if your Debit/Credit card is valid internationally

To directly answer your question about the legitimacy of these emails, please take a look at the following support articles:

• Identify legitimate emails from the App Store or iTunes Store - Apple Support
• Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

The next thing to verify is: Did you, at some time, request more iCloud storage space for your Apple ID, other than what Apple provides you for free? If not, then this would be a good indicator that these are SPAM messages.

Apple typically does not send out multiple emails daily. They also address you by your name that is on record with your Apple ID. They don't contact you as "Dear Customer" or "Dear Client."

See the pic below which is self explanatory