If you want to get back deleted emails from your Outlook, then you have to follow some steps for that.

  • Go to your Outlook app.
  • Tap on “Deleted Items” in the inbox you want to recover.
  • Hit the “Recover items recently removed from this folder”
  • Choose the emails that you would like to restore and press “OK” or “Select all” to select all emails and then Tab “OK” to restore them.

See also - https://www.latesttechnicalreviews.com/how-do-i-stop-duplicate-emails-in-outlook/