Using Classic Outlook on Windows for personal email, calendar, and contact management
Based on your description, your account has likely been blocked due to multiple failed login attempts. This is a security measure to protect your information.
I recommend first trying the Microsoft Sign-in Helper and checking whether it provides an option to regain access to your account:
https://go.microsoft.com/fwlink/?linkid=2196140
If that does not help, some users who experienced a similar issue reported that waiting at least 24 hours before attempting to sign in again allowed the temporary block to expire. Once the waiting period has passed, try signing in again and see if access is restored.
Honestly, if none of the options above work, the Account Recovery Form is unfortunately your last available recovery option. You can fill out the Microsoft account recovery form here: https://account.live.com/acsr
For security and privacy reasons, Microsoft Support cannot manually unblock or recover the account on your behalf, so the recovery form remains the primary path to regain access.
When completing the form, try to use a familiar device and location, and provide as much accurate information as possible.
You can submit the form up to two times within a 24-hour period, so feel free to include any additional details you remember with each submission.
To ensure that you have tried all available recovery options, you can also submit the Account Reinstatement Form here:
https://www.microsoft.com/concern/AccountReinstatement
Note: This is different from the Account Recovery Form.
The Microsoft team will review the reason your account was locked. If they determine that you are the rightful owner, they may reinstate access to the account. Responses are typically provided within 48 to 72 hours, so be sure to check your inbox, junk folder, and spam folder for updates.