Thanks for confirming, Rebecca. I understand how important this is, and I’ll do everything I can to help.
Since you’re using a personal Outlook.com account via browser, and the email is not in Junk, Deleted, or Recoverable Items, here’s the honest situation.
Outlook.com automatically remove spam and junk emails that are older than 30 days, and items deleted from Deleted Items can only be recovered for a limited window, also about 30 days. After that, they’re permanently removed from Microsoft’s servers and cannot be recovered by normal means.
Here's what you can try.
Check Inbox Rules
Go to https://outlook.live.com/
Click the Settings gear top right > View all Outlook settings
Go to Mail > Rules
See if any rules may have redirected or deleted emails silently
Check the archive and all mail folders
In the left pane, look for Archive or Folders > All Mail
Some messages may get moved there if not explicitly deleted
As a last resort, you can try contacting Microsoft Support and requesting an email recovery by providing the exact email address, subject, sender, and approximate date. This is not guaranteed, but for recent losses within 7-30 days, support can sometimes recover from back-end servers.
Moving forward, I would recommend turning on the Never delete spam option if you rely on catching missed emails later.
Consider creating an Outlook rule to keep a copy of all mail in a backup folder and regularly check Junk and Deleted folders before 30 days pass.
Here's how you can contact Microsoft Support:
Visit: https://support.microsoft.com/home/contact
Type Recover email in the search bar and press Enter
Scroll down and select "Sign in to contact support" or "Contact Support" if you're already signed in
Choose "Microsoft 365 and Office" under Product and services
Select "Outlook.com/Hotmail" under Category
Click "Chat with a support agent in your web browser" if available.