- In the left nav folder list, click on [Gmail]
- Right click on [Gmail] and select IMAP folders
- Press the Query button
- Subscribe to “[Gmail]/All Mail”
- Tick the box “When displaying hierarchy in Outlook, show only subscribed folders”
- Restart Outlook 2013
- If you do this and it still doesn’t work, then manually create a folder called ‘All Mail’ under the [Gmail] folder. Right-click on the folder and click Process Marked Headers.