How to create an All Mail folder in Outlook.
1. In Outlook, select the Folder tab.
2. Click New Search Folder.
3. Select Custom -> Create a custom Search Folder, and click Choose.
4. Name your search All Mail, and click OK.
5. You will receive a warning window. Click Yes to continue.
6. Click OK one more time.
7. Click All Mail under Search Folders to see all your mail.