How to Fix Outlook App Password Not Working
If you are trying to sign in to Outlook and the app password keeps failing, the issue is usually tied to Microsoft account security settings, outdated app authentication, or a device that is still using old credentials.
This guide explains the most common causes and the fastest fixes so you can get Outlook working again with less guesswork.
What an Outlook app password is
An app password is a one-time generated password used by older mail apps or devices that do not support modern authentication, also called OAuth or multi-factor authentication flows.
Microsoft often requires app passwords for legacy clients when two-step verification is enabled, especially on IMAP, POP, or older versions of Outlook for Windows, Outlook for Mac, and mobile mail apps.
When an app password stops working, the problem is rarely the password itself.
More often, the account has changed security settings, the app no longer supports legacy login methods, or the cached credentials on the device are stale.
Why Outlook app passwords fail
- Two-factor authentication changed: A new security update may invalidate old app passwords.
- Modern authentication is required: Microsoft 365 and Outlook.com increasingly block legacy sign-in methods.
- Incorrect account type: The account may be Exchange, Microsoft 365, Gmail, or Yahoo, each with different rules.
- Cached credentials are corrupted: Stored passwords in Windows Credential Manager or the app itself can override the correct password.
- Mail protocol settings are outdated: IMAP, POP, and SMTP settings may need new server names, ports, or encryption settings.
- Security defaults are enabled: Microsoft security defaults can disable app passwords entirely in some environments.
How to fix Outlook app password not working
1. Generate a new app password
If the old app password no longer works, create a fresh one from your Microsoft account security page.
App passwords are often single-purpose and can become invalid after a password reset, security policy change, or account recovery event.
Use the new app password exactly as shown.
Do not add spaces unless the app specifically requests them, and make sure you are entering it in the password field for the mail account, not in a browser or Microsoft sign-in form.
2. Remove the old account and add it again
Outlook may be holding onto outdated authentication data.
Removing the account and adding it back forces the app to rebuild the connection with current security settings.
- Open Outlook account settings.
- Delete the affected email account from the app.
- Restart Outlook or the device.
- Add the account again using the new app password or modern sign-in method.
This is especially effective after changing passwords, enabling multi-factor authentication, or migrating an account to Microsoft 365.
3. Clear saved credentials on Windows
On Windows, cached logins can cause Outlook to keep using an old password even after you enter the correct one.
The Windows Credential Manager stores sign-in tokens and passwords for Outlook, Office, and Microsoft services.
- Open Credential Manager.
- Check Windows Credentials and Generic Credentials.
- Remove entries related to Outlook, Office, MicrosoftOffice, or your email provider.
- Restart Outlook and sign in again.
For Microsoft 365 users, clearing credentials often resolves repeated password prompts and failed authentication loops.
4. Check whether your account still supports app passwords
Some Microsoft accounts no longer allow app passwords, particularly if security defaults or conditional access policies are active.
In Microsoft Entra ID, app passwords may be blocked by tenant settings, and personal Microsoft accounts may also shift toward stronger sign-in methods.
If you cannot find the option to create an app password, or the generated password is rejected immediately, your account may require modern authentication instead.
In that case, update the Outlook app or mail client to a version that supports current Microsoft sign-in standards.
5. Update Outlook and the operating system
An outdated Outlook build may not handle current authentication requirements.
This is common with older desktop versions, unsupported mobile mail apps, and older operating systems that have not received recent security updates.
- Install the latest Outlook updates from Microsoft 365 or Microsoft Store.
- Update Windows, macOS, iOS, or Android.
- Restart the device after updating.
Newer versions of Outlook usually support modern authentication better and reduce the need for app passwords altogether.
6. Verify IMAP, POP, and SMTP settings
If your email account uses manual server settings, a small configuration mistake can look like a password problem.
Authentication failures can happen when the server name, port, or encryption type does not match the provider’s requirements.
- IMAP: Used to sync mail across devices.
- POP: Downloads mail to one device.
- SMTP: Sends outgoing messages.
Confirm the correct incoming and outgoing server names with your provider, and check whether SSL or TLS is required.
For Microsoft accounts, using the auto-configured account setup is usually more reliable than manual setup.
7. Turn off and re-enable two-step verification if necessary
If an account security change caused the issue, resetting two-step verification can sometimes restore normal sign-in flow.
This should be done carefully, because disabling security features temporarily can expose the account if you do not immediately re-enable them.
After re-enabling two-step verification, generate a new app password and test Outlook again.
This is useful when app passwords were created before a major account security reset.
8. Test the account in Outlook on the web
Signing in successfully through Outlook on the web or the provider’s webmail confirms that the account itself is valid.
If web access works but the app fails, the problem is almost certainly with the local app setup, saved credentials, or unsupported authentication.
If web login also fails, the issue is broader and may involve account lockout, password reset, MFA approval problems, or tenant security policy restrictions.
Device-specific fixes
How to fix it on Windows
- Open Outlook in safe mode to rule out add-in conflicts.
- Clear cached credentials in Credential Manager.
- Repair the Office installation from Apps and Features.
- Recreate the mail profile in Control Panel if the profile is corrupted.
How to fix it on Mac
- Remove the account from Outlook for Mac.
- Check Keychain Access for stored Microsoft or Outlook credentials.
- Update Outlook from Microsoft AutoUpdate.
- Add the account again using the current sign-in method.
How to fix it on iPhone or Android
- Delete the account from the Outlook app or native mail app.
- Reinstall the app if the cache is corrupted.
- Make sure the app has permission to use account sign-in flows.
- Sign in again using the latest Microsoft authentication prompt.
When app passwords are no longer the right fix
Many users searching for how to fix Outlook app password not working are actually dealing with a legacy setup that needs modernization.
Microsoft 365, Exchange Online, and Outlook.com increasingly favor passwordless and modern authentication methods, including the Microsoft Authenticator app, security keys, and sign-in approvals.
If your mailbox is managed by an organization, the IT administrator may have disabled app passwords entirely.
In that case, the correct fix is not to keep retrying the app password, but to use a supported Outlook version or request a policy change from the administrator.
Quick checklist for failed Outlook sign-in
- Generate a new app password.
- Remove the account and add it again.
- Clear saved credentials on the device.
- Update Outlook and the operating system.
- Verify IMAP, POP, and SMTP settings.
- Check whether the account still allows app passwords.
- Test the account through webmail.
If the app password still fails after these steps, the most likely cause is account policy, unsupported authentication, or a corrupted local profile rather than a typing error.