Error 399287 – MFA SMS Blocked – [Moderator note: Personally Identifiable Information removed] Morocco Student

Question

Error 399287 – MFA SMS Blocked – [Moderator note: Personally Identifiable Information removed] Morocco Student

Marwan Bousserhane 0

Hello,

I am a student in Morocco and I cannot access my school Outlook account. I have been locked out for several days and I urgently need access to receive my Baccalaureate exam results.

Problem:

Every time I try to verify my identity using SMS or phone call, I immediately get the error:

"Sorry, we're having trouble verifying your account. Please try again."

The SMS or call never arrives — the error appears before anything is sent.

Important notes:

My phone number is correct and still mine, I have not changed it
The problem happens on all devices and all networks
I have no other verification method configured
My school administration cannot help at this time

I found that other Moroccan taalim.ma students had this exact same problem and Microsoft engineers fixed it from the backend by clearing the bad reputation flag (question 2283745 on Microsoft Q&A).

Please escalate this to your engineering team to unblock the SMS MFA reputation block on my account.

Account details:

• Email (UPN): [Moderator note: Personally Identifiable Information removed]@taalim.ma

• Tenant: taalim.ma

• Error Code: 399287

• Request ID: [Moderator note: Personally Identifiable Information removed]

• Correlation ID: [Moderator note: Personally Identifiable Information removed]

• Timestamp: 2026-06-14T12:35:20.313Z

• Methods failing: SMS and Voice Call

• Tested on: multiple devices and multiple networks

Thank you very much for your help.

User's image

VEMULA SRISAI 13,700 Reputation points Microsoft External Staff Moderator

2026-06-15T02:09:40.3266667+00:00

Marwan Bousserhane could you please share the requested details in private message.

3 answers

Your answer

VEMULA SRISAI 13,700 Reputation points Microsoft External Staff Moderator

2026-06-15T02:09:40.3266667+00:00

Marwan Bousserhane could you please share the requested details in private message.

Answer 1

Hello Marwan Bousserhane,

I have reached out to the engineering team to unblock MFA for your account. They have now unblocked it from the backend and removed the bad reputation on it. You should be able to log in to the Azure Portal without any issues.

Please try logging in and check if you can complete SMS authentication without any errors. Let me know if you encounter any issues.

I hope this information is helpful. Please feel free to reach out if you have any further questions.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". Thanks

Answer 2

Hi @Marwan Bousserhane,

Thank you for posting your question in the Microsoft Q&A forum.      

Regarding the issue where you’re unable to sign in to your account due to error code 399287, I understand how urgent this is for you, especially as you need access to your exam results.

For accounts like yours (school or student accounts under a tenant), authentication methods and MFA settings are fully managed by your organization’s administrator. Forum moderators do not have access to user accounts and cannot perform backend changes or escalate cases to engineering teams.

Since this is an MFA verification issue, I recommend that you contact your school’s IT administrator or support team and ask them to reset your MFA configuration. They can perform the following steps in the Microsoft Entra admin center:

Sign in to Microsoft Entra admin center with the admin account

Go to Users
Select the affected user account
Open Authentication methods
Revoke sessions
Select Require re‑register MFA
Save the changes

Revoke MFA sessions and require re-register in the Microsoft Entra admin center 

User's image

You could refer this article for a better view: Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID |… 

If you’re unsure who the Global Admin is within your organization, you can find guidance on locating them here: How do I find my Microsoft 365 admin? - Microsoft Support.               

Thank you again for your time and understanding. While my initial response may not resolve the issue immediately, I’d like to gather more details about your situation so I can assist you more effectively.     

I really appreciate your patience, and I’m here to help. Looking forward to your response!          

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".     

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Henry-N 15,065 Reputation points Microsoft External Staff Moderator

2026-06-15T15:04:08.0933333+00:00

Hi @Marwan Bousserhane,

Just want to check if you have any new update on the issue feel free to share here. Thank you so much for your cooperation we truly appreciate your time and effort. Looking forward to hearing from you soon.
Marwan Bousserhane 0 Reputation points

2026-06-16T11:44:15.0833333+00:00

Hello Henry,

Thank you for checking on me. Unfortunately the issue is still not resolved.

I just tried again and I still get the same error: "Sorry, we're having trouble verifying your account. Please try again."

The SMS and phone call both fail immediately. Nothing is received on my phone.

I also replied to VEMULA SRISAI in the private message with a screenshot and the new error details.

Thank you for your help.
Henry-N 15,065 Reputation points Microsoft External Staff Moderator

2026-06-16T14:29:39.17+00:00

Hi @Marwan Bousserhane,

Thank you for the update, and I’m sorry to hear that the issue is still ongoing.

Based on your scenario, since you are an end user of a school managed account, any actions such as raising a support ticket with Microsoft or making backend changes (including MFA-related fixes) must be performed by your organization’s IT administrator. Forum moderators do not have access to tenant data or the ability to escalate cases to the engineering team.

For school accounts, the official guidance is that you need to contact your institution’s technical support or IT team, as they are the ones responsible for managing user access and authentication settings

Try reaching out again to your school’s IT helpdesk, system administrator, or academic support office

If available, contact a teacher or school staff member who can escalate this internally

Request them specifically to:

Reset or reconfigure your MFA methods

Raise a support ticket with Microsoft on your behalf if needed

I truly understand this is not the ideal situation, especially given the urgency, but this is the only supported path for resolving access issues on organization-managed accounts.

Thank you for your patience and understanding.

Answer 3

Error 399287 indicates that the phone number has been blocked for SMS/voice verification because of a “bad reputation” flag on the Microsoft side. This cannot be fixed by changing devices, networks, or local settings.

Based on the documented resolutions for the same error:

The block must be cleared by Microsoft support (Data Protection team / Microsoft 365 support). Forum moderators or documentation cannot remove the flag.
In similar cases, Microsoft support resolved the issue by resetting MFA for the affected account or clearing the reputation block on the phone number.

Action required:

Contact the organization’s Microsoft 365 / Entra ID administrator or IT department and provide:
- Error code 399287
- Request ID, Correlation ID, and Timestamp from the error details
- Confirmation that SMS and voice MFA both fail and no other methods are configured
Ask the admin to open a support ticket with Microsoft (referencing that other tenants with the same error had it fixed by the Microsoft Data Protection team resetting MFA / removing the bad-reputation flag).

If there is only one administrator for the tenant and that admin is also locked out, that admin must contact Microsoft support by phone and work with the Data Protection team to verify identity and request an MFA reset for the tenant, as described in the referenced guidance.

Until Microsoft support clears the block or resets MFA, the account cannot be recovered through self-service because all available verification methods are failing.

References: