Managing personal Outlook.com account settings, security, and privacy
Please note that our Microsoft Q&A forum is a public platform, and we will modify your response/ 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'm very sorry to hear about what happened to your account. Losing access after seeing security information changed can be extremely stressful, and I understand your concern, especially since the account may contain important personal information.
Based on the details you've shared, it does appear that someone may have gained access to the account, added new security information, and removed the original recovery details before you lost access. The fact that your original email address is no longer recognized by the sign-in system is understandably concerning.
Unfortunately, this is a community forum, so we do not have access to Microsoft account records and cannot verify ownership, restore access, investigate account changes, or escalate cases directly to the account recovery team.
At this point, in addition to the recovery requests you've already submitted, I would recommend contacting Microsoft Support directly to see whether they can review the situation and advise on any available recovery options based on the evidence you still have, such as the security notification emails and the device that remains associated with the account. They may also be able to confirm whether there are any additional recovery channels appropriate for your situation.
I sincerely hope you're able to recover the account. If Microsoft Support provides any updates or requests additional information and you're unsure how to proceed, feel free to post back and the community will do its best to guide you.