Trouble logging into outlook app for my work email

Dear Andy,

Good day, and thank you for the detailed description of your issue, along with the screenshots. As a forum moderator, I genuinely wish I could directly access your account or delve into the backend systems to diagnose and fix this for you. Unfortunately, my role here is limited to providing general guidance and solutions that can be applied by users. 

Since the same work account signs in successfully on your other devices and Authenticator is working, your account and password are almost certainly fine. The problem appears to be specific to this phone, most likely relating to the authentication broker, device enrolment, or your organization's mobile access policy. Please follow these steps to see if they helps:

1.Device checks

On the affected phone:

Update all of the following through Google Play:

• Microsoft Outlook
• Microsoft Authenticator
• Microsoft Intune Company Portal, if installed or required
• Google Chrome
• Android System WebView

Turn off power-saving mode if it is enabled, and change the settings to allow the app to launch other apps.

Disable battery optimisation for Authenticator and Company Portal, so they can continue running in the background.

Open Microsoft Authenticator first, before opening Outlook, to make sure it is running.

Set the phone’s date and time to automatic.

Temporarily disable any VPN, private DNS, ad blocker, or security-filtering application, then test using both Wi-Fi and mobile data.

For reference: Failed to add Microsoft 365 account or cannot sync new messages with your existing Microsoft 365 account

2.Check Company Portal

Your employer may require the device to be registered, compliant, or protected by an Intune app policy.

1. Install or open Microsoft Intune Company Portal.
2. Sign in with the same work account.
3. Complete any device-registration or compliance steps.
4. Check whether Company Portal reports the device as compliant.
5. Open Authenticator, then reopen Outlook and add the account.

3.Contact technical support

If none of the above resolves it, please reach out to your IT administrator. Ask them to check:

• Microsoft Entra admin center > Users > Sign-in logs
• Microsoft Entra admin center > Devices
• Microsoft Intune admin center > Devices
• The user’s registered authentication methods
• Exchange Online mobile-device access

Using the timestamp of your failed attempt, they should be able to locate the specific sign-in and review the failure reason, error code, Conditional Access result, device compliance status, client application, and resource being accessed. That will identify exactly what is blocking it. If you don't know who your IT administrator is, please refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support 

I hope this information is helpful and provide you with a clear path forward. Should you have any further questions or need additional assistance, please don't hesitate to reach out. I'm always happy to help. Have a wonderful day! 

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