My personal Outlook.com mailbox cannot initialize.

The described pattern matches a mailbox-side Outlook.com issue, not a local device, browser, password, or network problem:

• Sign-in to the Microsoft account succeeds.
• OneDrive works.
• The same failure occurs in Outlook.com, People, and the Outlook mobile app.
• A different Outlook.com account works on the same devices.
• Password reset and storage checks were already completed.

There is no documented self-service method to inspect or repair Outlook.com backend mailbox provisioning or server-side mailbox state for a personal/free Outlook.com account.

Supported next steps:

1. Try the Outlook.com account unblock flow if the account was temporarily blocked due to unusual sign-in activity: Sign-in Helper.
2. If the account is not blocked and Outlook.com still fails, contact Outlook.com support from the Outlook.com help experience:
   • Sign in to Outlook.com.
   • Select Help or the ? icon.
   • Search for a mail access issue such as cannot receive emails.
   • Scroll to Still need help? and select Yes.
   • Choose Chat with a support agent in your web browser.
   • Submit the request and provide the failure details.
3. If sign-in to Outlook.com is not possible at all, use the sign-in recovery path: When you can't sign in to your Microsoft account.

When submitting the support request, include:

• That this is a personal/free Outlook.com account.
• That Microsoft account authentication succeeds and OneDrive works.
• That Outlook.com, People, and Outlook mobile all fail for the same account.
• That another Outlook.com account works on the same devices and browser.
• That password reset was already tried.
• That storage is not full.
• The UTC timestamps, Client ID, Session ID, Request ID, server names, client version, and the HTTP 500 / StartupData / ServerError details.
• That mailbox contents must be preserved and no delete/recreate action should be taken without confirmation.

A similar reported pattern has previously required Microsoft-side remediation rather than user action.

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