Authentication on exchange

Hi @Jeska,

Welcome to the Microsoft Q&A forum.

Thank you for reaching out. I appreciate you taking the time to share your experience, and I’d be happy to help investigate the sign‑in issue you’re encountering with Outlook for Android.

To better understand why you’re seeing repeated authentication prompts, I’ll need a few additional details. These will help determine whether the issue is related to the app itself, authentication settings, or your email server configuration:

1/ Are you using Multi‑Factor Authentication (MFA)?

Outlook for Android may fail to sign in if Microsoft Authenticator is missing, outdated, or not fully configured.

2/ Have you recently changed phones or updated your authentication device?

If you moved from an old device to a new one, please confirm whether the authenticator app has been set up on the new phone. Authentication can sometimes fail after a password change or device migration, especially if older sign‑in tokens are still stored.

3/ Is your email hosted on Microsoft 365 or an on‑premises Exchange server?

In some cases, recent sign‑in issues have affected Outlook mobile specifically, while other mail apps continued to work normally due to backend service behavior.

4/ Does your email work on other devices or apps, such as Samsung Mail, Apple Mail, or Outlook on the web?

If other apps sign in successfully, this helps confirm that the issue is isolated to the Outlook mobile app.

5/ Have you already tried clearing Outlook’s app data on your Android device?

Doing so removes cached credentials that may be preventing a successful sign‑in.

6/ Is your device’s date and time set to update automatically?

Incorrect date or time settings can interfere with secure authentication processes.

Once I have a clearer picture of your setup, I’ll be able to assist you more accurately. Please feel free to share any additional details (with personal information removed) you think may be relevant. Screenshots, if available, are especially helpful and greatly appreciated.

In the meantime, you can try the steps below, as they often resolve similar issues:

1/ Clear Outlook app data completely:

On your Android device, go to Settings > Apps > Outlook > Storage > Clear Data.

2/ Enable automatic date and time settings:

Incorrect time or time zone settings can prevent authentication from completing successfully.

Steps: Settings > General management > Date & Time, then turn on Automatic date & time and Automatic time zone.

3/ Sign in through the web first:

Please log in to outlook.com using a web browser to confirm that your credentials are working. If additional verification is requested, complete it before signing back into the mobile app.

I appreciate your understanding regarding the scope of support available through this forum. As moderators, my role is to provide general guidance and assist with common troubleshooting steps. While I do not have access to internal systems or administrative tools required to resolve account-specific or backend-related issues but I’ll continue doing our best to support you within the scope of our responsibilities.   

I hope this information is useful. As other users will also be searching for guidance in this community, clicking “Accept Answer” would be a wonderful way to amplify your impact. Your action not only helps others with similar questions find the right solution faster, it also highlights your role in shaping a more helpful and informed community.    

Thank you again for your time and for raising this important usability concern. If you have any further questions or need additional assistance, please don’t hesitate to reach out. 

I look forward to your thoughts on this. 

Note: Please follow the steps in our documentation to enable email notifications if you want to receive notifications related to this thread.

For Outlook for Android repeatedly prompting for sign-in even though the username, password, domain, and server are correct, the behavior usually indicates that the app cannot successfully auto-discover or connect to the mail server with the provided settings.

Use these steps:

1. Verify server settings
   • In Outlook for Android, when the advanced screen appears asking for Server, Domain, and Username, confirm these values against the configuration provided by the mail administrator.
   • The Username may be different from the email address; some organizations require domain\username or a specific logon name.
   • If a Windows domain is required, enter the domain name exactly as provided by the administrator.
2. Re‑check for typos
   • A typo in the email address or password will cause auto-discover to fail and trigger the advanced server/domain prompt.
   • Go back to the simple login screen (tap Hide advanced settings) and re-enter the email and password carefully to retry auto-discover.
3. Confirm server is reachable from the Internet
   • If the mail server is not auto-discoverable over the Internet, Outlook for Android will always require manual server details.
   • If the correct server/username/domain are unknown, contact the mail administrator for the exact mobile/Exchange/IMAP configuration details.

If the problem persists after confirming all values, the mail administrator must verify that the server is correctly published and supports the connection method being used by Outlook for Android.

References:

• [Exchange] I entered my Email and Password correctly, why is your app asking for Server and Domain now?