Using Outlook for Android for personal email and calendar management
I recommend first checking whether the issue occurs within the Outlook application or directly with your Microsoft account. Please open a web browser and visit https://account.microsoft.com/security, sign in with the affected Microsoft account, and select Manage how I sign in > Add a new way to sign in or verify. Try adding the recovery email address there and completing the verification process.
Since you have already attempted verification several times, avoid repeatedly requesting new codes for now, as Microsoft may temporarily restrict verification attempts following excessive requests.
Could you clarify whether the authentication error appears immediately after entering the recovery email address or only after entering the verification code? Also, are you trying to add a new recovery email to an account you can still access, or are you attempting to recover access to an account you cannot sign in to? If possible, please share a screenshot showing the exact error message, with your email address and other personal information hidden. This will help determine whether the problem is related to temporary verification restrictions, the recovery email itself, or Microsoft account authentication. If you cannot access your account at all, you can also use Microsoft's official Sign-in Helper to identify the available recovery options.