IMAP authentication fails with "User is authenticated but not connected" for my Outlook.com account

Jim 0 Reputation points
2026-10-01T17:54:50.77+00:00

Hello,

I am writing about my personal Outlook.com account: [Moderator note: PII removed]@hotmail.com

Problem: IMAP authentication consistently fails. When authenticating via IMAP (XOAUTH2) to outlook.office365.com:993, the server responds:

NO User is authenticated but not connected.

What I have verified:

The OAuth token is valid and accepted (authentication succeeds; the failure is specifically "not connected")

SMTP works normally (smtp-mail.outlook.com:587, same token, AUTH XOAUTH2 succeeds)

Webmail works normally (outlook.live.com — can read and send mail)

Mobile Outlook app works normally (same account)

The "Allow mail apps and devices to use Sync" setting (Settings → Mail → Synced Devices) is ON; I toggled it OFF and back ON and waited more than 10 minutes — no change

I tested all IMAP endpoints (outlook.office365.com, imap-mail.outlook.com, imap.outlook.com) — all return the same "not connected" error

I changed my account password and re-authorized my mail client — still the same error

Request: Could you please check the IMAP protocol state of this mailbox on your side and reset/reconnect it? It appears the mailbox is marked as "disconnected" for IMAP only, while SMTP, web, and mobile access all work fine.

Thank you.

Outlook | Web | Outlook.com | Email
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  1. Lychee-Ng 28,915 Reputation points Microsoft External Staff Moderator
    2026-10-02T10:43:33.8266667+00:00

    Thanks for sharing what you've tried, Jim.

    Please note that our forum is a public platform, and we will modify your question to hide private, identifiable information in the description. Kindly ensure that you hide such details the next time you post to protect personal data. 

    Just wondering, have you ever checked out this article from Microsoft: POP, IMAP, and SMTP settings for Outlook.com | Microsoft Support? It documented an IMAP issue I found pretty similar to what you're facing, with a workaround. I think it's worth trying:

    1. Sign into https://account.live.com/Activity with the affected Microsoft account.
    2. Locate and expand the entry around the time of your recent failed IMAP connection.
    3. If you see This was me / Authorize... / similar option > select it and try connecting again.

    If the Recent activity workaround does not resolve it, I recommend reaching out to the support team directly. Microsoft Q&A is just a user-to-user public forum, so we cannot inspect or reset the IMAP state of an individual mailbox as you requested. Only Microsoft Support has access to backend system:

    • In Outlook, select Help (?) on the menu bar > enter the IMAP problem
    • If the suggestions do not resolve it, scroll to Still need help? > select Yes.

    When requesting help, include as much information about your setup and what you've tried as possible. That will help them narrow down the issue easier and skip the unnecessary steps.

    Was this answer helpful?

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