I can't login into my outlook.com mail

Question

When I try to switch from my personal to my office outlook accounts I get this error

UTC Date: 2026-07-10T19:26:39.378Z
Client Id: [Moderator Note: Personal Info Removed]
Session Id: [Moderator Note: Personal Info Removed]
Client Version: 20260703008.05
BootResult: fail
Back Filled Errors: None
err: Error: 440
esrc: StartupData
et: ServerError
estack: Error: 440
    at Object.w [as createStatusErrorMessage] (https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.87a8e2c4.js:1:806)
    at https://res.public.onecdn.static.microsoft/owamail/hashed-v1/scripts/owa.mailindex.87a8e2c4.js:1:188599
st: 440
efe: [Moderator Note: Personal Info Removed]
reqid: [Moderator Note: Personal Info Removed]
cv: [Moderator Note: Personal Info Removed]

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Moved to Outlook | Web | Outlook on the web for business | Sign in

Answer 1

Hi Lance Yates,

Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

I understand that you receive Error 440 when switching between your personal Outlook.com account and your work Outlook account.

This error may be caused by conflicting or expired browser sign-in information. Please try the following:

• Sign out of all Microsoft accounts and close all browser windows.
• Open an InPrivate or Incognito window.
• Sign in separately using the correct portal:
  • Personal Outlook.com account: Outlook.com
  • Work or school account: https://outlook.office.com/
• If it works in private browsing, clear the Microsoft/Outlook cookies and cached data in your regular browser.

You can also try another browser, network, or device and temporarily disable any VPN or browser extensions.

If the personal account still cannot be accessed, please use the Microsoft Account Sign-in Helper. If only the work account is affected, please contact your organization’s Microsoft 365 administrator.

Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas only.

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