Outlook desktop (M365, current channel, build 2606) can't sign in to Gmail via "Google - IMAP" — persistent, not resolved by updating

Question

Gmail account (POP/SMTP fallback in use since IMAP OAuth broke) stopped syncing new mail after ~10/29/2024. Adding the account fresh in Outlook reaches 'Adding this place to your Office account...' and after 60-90+ seconds fails with: 'Google - IMAP: Sorry, we could not sign you in to Google - IMAP. Please try again later.' This happens consistently across multiple attempts over several hours, on a fully updated Outlook build (2606, Current Channel) - so this isn't the older-build issue described in the existing KB articles. Gmail's own 'optional connected experiences' setting is already enabled. Anyone else still seeing this in July 2026, or know if this is a known outage on Microsoft's end?

Answer 1

Resolution (of sorts): New Outlook for Windows works, classic Outlook still doesn't.

@Hornblower409 - yes, it OAuths. I installed New Outlook for Windows from the Microsoft Store and added the Gmail account there. When adding it, New Outlook shows an explicit "Sync your Gmail account" prompt stating it will request full permissions ("your emails, calendar events, and contacts will be synced to the Microsoft Cloud when you sign in and accept all permissions"). Signing in through that flow succeeded immediately, and new mail has been flowing into the account ever since (verified directly against Gmail's own webmail).

Classic Outlook still fails exactly the same way as before: the Google consent screen it triggers only ever asks for name/profile picture/email, never the full Gmail access scope, and it ultimately fails with "Sorry, we could not sign you in to Google - IMAP. Please try again later." So this looks like a bug isolated to classic Outlook's Google-IMAP OAuth implementation specifically - something in how it constructs the auth request or handles the local redirect - not a Gmail-side or account-side problem.

Switching to New Outlook for this account as my day-to-day workaround. Posting this in case it helps anyone else stuck on the same classic Outlook issue, and in case it's useful signal for whoever owns that OAuth flow on the classic Outlook side.

Answer 2

@Neal Kurzner said

so this isn't the older-build issue described in the existing KB articles

Are you referring to "Unable to add a Gmail account to classic Outlook" at?
https://support.microsoft.com/en-US/Support/known-issues/unable-to-add-a-gmail-account-to-classic-outlook

Or the similar process at?
https://support.microsoft.com/en-US/Support/known-issues/users-get-errors-0x800ccc0e-0x800ccc0f-synchronizing-gmail-and-yahoo-accounts-in-classic-outlook

Because the steps under "Manual Workaround" and "WORKAROUND" in those articles (removing all traces of the GMail account and credentials, revoking the MS Access in Google) is still a suggested fix for when a GMail OAuth gets caught in "limbo".