Using classic Outlook for Windows in business environments
Good day, and thank you for sharing the details of your concern.
From what you shared, access through webmail appears to be working, and the Authenticator app is still usable for actions such as password or security updates. However, when setting up the account in Classic Outlook on a new computer, the sign-in is blocked by a request to approve through the Authenticator app, no notification is received, and only a certificate-based option is offered.
This may happen if Classic Outlook is using a sign-in method that relies on a certificate-based option currently associated with your account. Other applications, such as webmail, may continue to work normally because they might still be using a previously signed-in session or a different sign-in path, and therefore do not require the same type of approval at this time.
To help move this forward, you may find it helpful to try the following steps:
1/ Check Authenticator App notifications
Please make sure notifications are enabled for the Microsoft Authenticator app on your phone and that the device has a stable internet connection. If notifications are off or delayed, approval requests may not appear.
2/ Verify the correct account in Authenticator
Please confirm that the same work account you are trying to add in Outlook is already set up in the Microsoft Authenticator app. If a different or incomplete account is present, the approval request may not be delivered correctly.
3/ Contact your IT administrator
If you are either an admin or end-user in your company, please check if there are other IT admins who still have access and contact them. They can confirm whether other sign-in methods (such as phone or SMS) are enabled and available for your account by going to https://entra.microsoft.com/ > Authentication methods > Policies.
Additionally, you can also share with them the guidance from this article Manage user authentication methods for Microsoft Entra multifactor authentication. This will help them assist you in resetting your MFA settings and restoring access to your account. Once your admin completes this process, your previous sign-in sessions will be cleared, and the next time you log in, you will be prompted to set up MFA again from scratch.
In case you do not know who is your IT admin, kindly refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support.
4/ Contact Microsoft support
If you are the only admin in your company, the appropriate course of action would be to contact the Data Protection Team. To reach out to them, you can try calling your regional Microsoft support hotline here: Global Customer Support.
During the phone call, you will need to provide the information associated with your subscription, such as your company name, billing details, phone number, and an alternate email address, etc. This information allows the Data Protection team to verify your identity and securely assist you in regaining access to your administrator account.
In some regions, the initial interaction may be automated, so here’s a general idea of how the conversation might go to help you prepare:
(When you call the support number, you may hear an introduction of about 30 seconds such as "you can visit the link...". You can ignore this introduction and wait until you are presented with the options. Then press "1" as a business email user, and again "1" for technical help.)
In some countries, it is an automated conversation like:
IVR: What kind of problem are you concerned about?
You: Authenticator.
IVR: What kind of product do you use?
You: Office 365 for business.
IVR confirmation: education or company account?
You: For companies
IVR: Are you an administrator?
You: Yes.
IVR: Do you have another administrator in your organization?
You: No.
IVR: Do you need a... Service request?
You: Yes. I need to create a ticket. Please send me directly to the Data Protection Team.
Please note that forum moderators do not have access to user account settings and cannot assist with logging in, resetting passwords, or changing access rights. While we do not have access to internal systems or administrative tools required to resolve account-specific or backend-related issues, we’ll continue doing our best to support you within the scope of our responsibilities.
I hope the information provided helps guide you in the right direction. Although I’m unable to take direct action, I sincerely hope that the steps and recommendations I’ve shared can support you through the process.
If you find my post useful, kindly consider upvoting it. Doing so can assist others in the community who may have similar questions in finding solutions more quickly.
Thank you for your kindness and contributions to the forum.
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