How do I update an existing Microsoft Hotmail or Outlook.com account to use OAuth 2.0?

If you used your Microsoft account password when adding a Hotmail/Outlook.com account to K-9 Mail, you will need to use what Microsoft calls “modern authentication” to still be able to access your messages after October 1, 2022. For this to work, make sure you’re using K-9 Mail 6.200 or newer.

  1. Go to Settings → [Your account] → Fetching mail → Incoming server.

  2. Change IMAP server to outlook.office365.com. If you only see “POP3 server”, you can’t update the account. Please remove the account from K-9 Mail and add it again.

  3. Select OAuth 2.0 under Authentication.

  4. Tap the Next button.

  5. If your browser is not already logged in to your Microsoft account, you will be asked to log in.

  6. Afterwards you’ll be asked to grant K-9 Mail permission to:

    • Read and write access to your mail
    • Access to sending emails from your mailbox
    • Maintain access to data you have given K-9 Mail access to

    Tap “Yes”.

  7. Go to Settings → [Your account] → Sending mail → Outgoing server.

  8. Change SMTP server to smtp.office365.com.

  9. Select OAuth 2.0 under Authentication.

  10. Tap the Next button.

  11. K-9 Mail will automatically use the access you’ve granted it in step 6.

  12. Your Microsoft account in K-9 Mail should work again.

3 Likes