Hy: Casper,
There are a few possible reasons why you are getting these emails, and some steps you can take to stop them. Here are some of my suggestions. I think it might find you helpful:
1: Report all the emails as phishing or scam. This will help Microsoft to identify and block the sender, and prevent them from sending you more emails. Also, you can block the sender manually by adding them to one of your blocked sender lists.
2: The second you can do is delete all the emails and not click on any links or attachments. because some of these emails may contain malicious software or the scammer is trying to trick you into revealing your personal information. Do not reply to them or provide any information they ask for.
I hope these tips will help you to stop receiving single-use code emails. If you have any other questions or concerns, please feel free to ask me. I’m always happy to help you.