Unable to add Gmail to Outlook Account - Authentication Error

Allan Trebilco 0 Reputation points
2026-09-13T20:09:00.45+00:00

Samsung Galaxy S25 Ultra.
I was having issues with my gmail account connected to outlook in the last few days, and noted the inbox would not update.
I started by deleting my gmail account as I was planning to re-add it.

Since then, I cannot add my Gmail account to Outlook for Android using Google authentication. Google authentication and permissions complete successfully, but when control returns to Outlook I receive “An error occurred during authentication. Please try again later.”

I have already cleared Outlook cache/data, force-stopped Outlook, restarted the phone, uninstalled/reinstalled Outlook, confirmed Chrome is the default browser, confirmed Outlook supported-link handling is enabled, revoked Microsoft Apps & Services access from my Google account and reauthorized it, and confirmed the Google account/calendar sync correctly at the Android level.

The Gmail account works successfully in Outlook using manual IMAP with a Google App Password. The problem seems to be specifically the Google OAuth account-add process in Outlook for Android.

Outlook | Outlook for mobile | Outlook for Android | For home
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  1. AI answer

    2026-09-13T20:09:21.5833333+00:00

    Since manual IMAP with a Google App Password works, the failure is isolated to the Google OAuth add-account flow in Outlook for Android rather than Gmail credentials or Android account sync.

    Supported checks and next actions:

    1. Confirm Gmail IMAP is enabled.
      • In Gmail on the web: Settings > Forwarding and POP/IMAP > under IMAP Access, select Enable IMAP > Save Changes.
    2. Confirm Gmail folders are exposed to IMAP.
      • In Gmail on the web: Settings > Labels.
      • Make sure Show in IMAP is selected for at least Inbox, Sent Mail, Trash, and All Mail.
    3. Try adding the account again using the normal Google sign-in flow in Outlook for Android.
      • Outlook for Android supports Gmail two-step verification and shows a screen to enter the verification code when required.
    4. If OAuth add still fails, use the IMAP setup path in Outlook for Android as the working workaround.
      • In Outlook for Android: Settings > Add Account > Add Email Account.
      • Enter the Gmail address, tap Continue, then choose IMAP.
      • Turn on Advanced settings and use these settings:
        • Incoming server: imap.gmail.com
        • Port: 993
        • SSL: Yes
        • Outgoing server: smtp.gmail.com
        • Port for SSL: 465
        • Port for TLS/STARTTLS: 587
        • Requires authentication: Yes
        • Username: full Gmail address
        • Password: Gmail password
      • Complete setup with the checkmark.
    5. If the password was recently changed, update it at the email provider first, then re-enter it in Outlook for Android. If Outlook still does not sync after a password change, delete the account and add it again.

    What is supported by the available guidance:

    • Outlook for Android supports Gmail two-step verification.
    • Gmail must have IMAP enabled before it can connect.
    • Outlook for Android supports adding Gmail by IMAP/POP when needed.
    • Only email sync is available when using IMAP/POP; calendar and contacts do not sync through that setup.

    References:

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  2. Thomas4-N 21,570 Reputation points Microsoft External Staff Moderator
    2026-09-14T13:05:28.6333333+00:00

    Hello Allan Trebilco,

    Given everything you’ve already tested, I don’t think repeating the usual cache, reinstall, or IMAP steps would add much.

    At this point, I’d keep the manual IMAP setup as the workaround and report the failed Google account authentication flow through Outlook > Settings > Help & Feedback > Contact Support, so the Outlook mobile support team can investigate the app-side sign-in failure.

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