I can't verify my university account because I no longer have the phone number or access to the authentication app.

Hi,

If you no longer have access to your old phone number or Microsoft Authenticator, you will need your university's IT administrator/help desk to reset your MFA/security information or require you to register a new authentication method.

Please contact your university's IT support team using their official support channel and let them know that:

• You no longer have access to the phone number previously registered for MFA.
• You no longer have access to the Microsoft Authenticator app/device.
• You need your MFA/security information reset so you can register a new authentication method.

There is no general Microsoft Gmail address where you can send your new phone number or account information. For a university account, the university's IT administrator manages the account and authentication settings.

If your university has provided a self-service password/MFA recovery portal, you can also try that first.

Microsoft guidance: Reset your Microsoft work or school account password using security info | Microsoft Support

However, if MFA is required and you cannot complete the verification, the university IT administrator will need to assist with the reset. For more information on how an administrator can require a user to re-register for MFA, please see: Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID |…

I recommend contacting your university IT/help desk directly and asking specifically for an MFA reset or new authentication method registration.