I received the same email:
iTunes Store <do_not_reply@itunes.com>
On 01/03/2024 you are scheduled to be charged $9.99 for iCloud+ with 2 TB of storage, but there is a problem with your payment information.Please update your payment information as soon as possible. If we cannot successfully charge your account, it will be downgraded to the free 5 GB plan and your service may be affected.Follow the instructions below to update your billing information:
1.Go to Settings > [your name] > iTunes & App Store.
2.Tap your Apple ID, then tap View Apple ID. You might be asked to sign in.
3.Tap Manage Payments (if you’re using an older version of iOS, tap Payment Information) and follow the prompts.
You can also update your billing information on a Mac or PC.The iCloud Team
I hadn't seen the iTunes store email address and thought this was a legitimate Apple email. The blue link just leads to an Apple Support page. I'm just worried that clicking on the link may have left some form of malicious script on my computer. So a) do people think this was a glitch email from Apple and b) if it's malicious, what next step should be taken. I haven't seen any other unusual activity on my accounts.
Thanks everyone!