I can't access to my onmicrosoft email due to MFA error

Dear Mhd Salah Mhd Ziad Halwani
Thank you for reaching out to the Microsoft Q&A forum.

I understand how inconvenient and frustrating it can be to lose access to your administrator account due to authentication issues. Let's find the best way to resolve this issue. 

Based on your description and the screenshot you provided, it appears you're encountering error code 399287, which is typically associated with issues such as failed authentication, timeouts during the sign-in process, or problems with your current multi-factor authentication (MFA) setup, including potential SMS verification failures.

As a temporary workaround, you might consider switching to an alternative authentication method, such as the Microsoft Authenticator app, email verification, or another MFA option to regain access.

Since the exact cause wasn’t mentioned, the solution may vary depending on your situation:  

If you are not the only Gobal Administrator:  

We recommend reaching out to another Global Administrator in your organization who can reset your Multi-Factor Authentication (MFA) configuration. You can also refer to this Microsoft support article for more information: Manage authentication methods - Microsoft Entra ID | Microsoft Learn. As a moderator, we do not have administrative access to change these settings. 

If you are the sole Global Administrator and find yourself completely locked out of the tenant: 

You may need to reach out to us via our customer service phone number: Customer service phone numbers - Microsoft Support. An agent will be able to create a ticket for you under the affected tenant and then escalate this ticket to the Data Protection team, who can assist you in regaining access. 

I hope this helps clarify your situation and guides you toward regaining access to your accounts. If anything’s unclear or you need help with the next step, feel free to reach out.  I'm here to help and support you through this process. 

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