Managing personal Outlook.com account settings, security, and privacy
This message means Microsoft’s automated anti-abuse system blocked the registration before the account was created.
Please stop making further attempts for at least 24 hours. Then open
on another device, use a normal home or mobile-data connection, and turn off any VPN, proxy, Private DNS or ad blocker. Use a completely new email name and, when possible, verify with a different phone number.
Microsoft’s official guidance also recommends using another device or an alternative sign-up method: https://support.microsoft.com/en-us/accounts-billing/manage/how-to-create-a-new-microsoft-account