My account has been hacked

Hi, I'm John! I will help you with this.

Check if you still have access to your Microsoft account and make sure you're currently signed in https://account.microsoft.com/ If you’re locked out, let me know.

Just to be safe, I’d recommend to sign out everywhere. Visit: https://account.live.com/proofs/manage/additional Scroll down to Sign me out and select "Sign me out".

In Outlook.com, go to Settings > View all Outlook settings > Mail > Rules and Mail > Forwarding to make sure no one has set up rules to forward or delete your messages.

And changing your password again and enabling two-step verification if you haven’t already. This will add an extra layer of security to prevent future unauthorized access.

"What is: Multifactor Authentication" https://support.microsoft.com/topic/what-is-multifactor-authentication-e5e39437-121c-be60-d123-eda06bddf661

About the missing email:

Since your account was compromised, it’s possible the attacker deleted or moved your old emails.

Please check your Deleted Items folder and click “Recover items deleted from this folder” at the bottom, sometimes older messages can still be restored from there. Also check your Archive or Junk Email folders. "Recover and restore deleted items in Outlook" https://support.microsoft.com/office/recover-and-restore-deleted-items-in-outlook-49e81f3c-c8f4-4426-a0b9-c0fd751d48ce

If the emails don’t appear under “Recover items deleted from this folder,” it means they’ve been permanently removed from the mailbox and unfortunately can’t be recovered.

To prevent this from happening again, I recommend turning on two-step verification and reviewing your recent activity page to make sure your account is fully secure. "How to help keep your Microsoft account secure" https://support.microsoft.com/account-billing/how-to-help-keep-your-microsoft-account-secure-628538c2-7006-33bb-5ef4-c917657362b9

Let me know if you have any further questions or concerns.