Dear MaFaTra,
Good day! Thank you for posting in the Microsoft Community. We will be happy to help you.
Based on your description, you're having concern with emails requesting a single-use code to your account.
To better understand and investigate your problem, I may need more detailed information from you so that I can narrow down the problem in the right way:
Are you using Microsoft365 business account(******@xxx.onmicrosoft.com/******@yourdomain.com) or personal account (which is ended with outlook.com/hotmail.com/live.com/msn.com)?
Since different types of accounts are supported by different support teams on the forum, after getting the detailed information, I will provide more information accordingly.
As I know, it is highly likely that these emails are part of a phishing scam. Microsoft will never send unsolicited emails asking for personal information or single-use codes.
To put an end to these messages, you can mark them as spam or phishing in your email client. This will help your email provider to identify similar messages in the future and prevent them from reaching your inbox.
Additionally, you can report the phishing attempt to Microsoft by forwarding the email to reportphishing@Microsoft.com. This will help Microsoft to investigate and take action against the scammers.
I look forward to your next update for a more detailed analysis. Thank you very much for your cooperation.
Thank you for your precious time. Have a nice day.
Sincerely,
Microsoft Community Moderator