- Does 'Outlook Authentication Failed' mean my account is hacked?
- Not necessarily. The most common causes are an expired password, a recently changed password not updated in Outlook, or a security policy change at your email provider. Check your account login in a browser first before assuming the worst.
- Will I lose my emails if I fix this?
- No. Your emails are stored on the mail server, not in Outlook itself. Removing and re-adding your account in Outlook may remove local copies, but they will re-download from the server once reconnected.
- How do I fix Outlook Authentication Failed?
- Go to File → Account Settings → select your account → Change → update your password. If your provider uses two-factor authentication, you'll need to generate an 'app password' in your email provider's security settings and use that instead of your regular password.