Share via

Why is Outlook 2016 imap to google failing since yesterday

CD 20 Reputation points
2026-05-08T09:07:02.5533333+00:00

All of the sudden, none of my gmail imap accounts will work in Outlook. I even removed the accounts, deleted Microsoft services from third-party apps and try to re-add the account. it says cannot connect to the server.

Outlook | Windows | Classic Outlook for Windows | For home

Answer accepted by question author

AI answer

2026-05-08T09:07:22.6166667+00:00

Outlook 2016 IMAP connections to Gmail are failing because Office was previously granted incomplete or incorrect access to the Google account, or because the stored OAuth2 credentials for Gmail in Windows are now invalid. This causes errors such as “We couldn’t log on to the incoming (POP/IMAP) server” or “cannot connect to the server” when Outlook tries to connect to Gmail via IMAP.

To fix this for classic Outlook with Gmail IMAP:

  1. Confirm Gmail IMAP is enabled
    • In a browser, go to Gmail.
    • Open Settings → Forwarding and POP/IMAP.
    • Under IMAP Access, make sure Enable IMAP is selected.
    • Select Save Changes.
  2. Remove Microsoft apps & services access in Google
    • Close Outlook.
    • Sign in to the Google account at Google.com.
    • Select the profile picture → Manage your Google Account.
    • Go to Security.
    • Under Your connections to third-party apps & services, select Microsoft apps & services.
    • Find Microsoft apps & services has some access to your Google Account and select See Details.
    • Under Access you've given to Microsoft apps & services, select Remove all access, then Confirm.
  3. Delete the stored Google IMAP OAuth2 credentials
    • Open Credential Manager from the Windows Start menu (on some systems via Control Panel → Credential Manager).
    • Select Windows Credentials.
    • Under Generic Credentials, locate entries starting with MicrosoftOffice16_Data:OAUTH2.
    • Expand each and hover over the name to see the full value including tp_google_imap_Oauth2; these are the Gmail credentials.
    • Remove each credential that matches MicrosoftOffice16_Data:OAUTH2 (there are two per Gmail account; remove both for the affected accounts).
  4. Re-add the Gmail account in Outlook and grant full access
    • Start Outlook and add the Gmail account again.
    • During the browser-based Google sign-in, ensure the checkbox for allowing Microsoft apps & services to “Read, compose, send, and permanently delete all your email from Gmail” is selected before continuing.

If running a newer Current Channel build (Version 2412 Build 18324.20168 or later) and an error dialog appears during setup, use the Retry link in that dialog to repeat the browser sign-in and this time select the required access checkbox.

If Outlook.com connected accounts were previously used, note that Microsoft has removed the ability to connect new third-party accounts such as Gmail directly in Outlook.com; in that case, Gmail must be accessed via Outlook as a separate account rather than as a connected account in Outlook.com.

References:

AI-generated content may be incorrect. Read our transparency notes for more information.

Was this answer helpful?

2 people found this answer helpful.

0 additional answers

Sort by: Most helpful
Most helpful Newest Oldest

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.