Hi, I'm John! I will help you with this.
To help narrow down the issue:
- First, are the emails still in your Deleted Items folder, or are they gone completely?
- Did you receive any alerts, notice unusual activity, or received any notice that your security info was changed (email/phone updated)?
In the meantime, if you haven’t already:
In https://outlook.live.com/mail 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.
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.
If you still have access, 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".
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.
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
I really hope this information is helpful! Let me know if you have any further questions or concerns.
Regards,
John J.D.