For each folder, you can specify what should happen to old messages, and after what time messages are considered to be old.
Set AutoArchive Options for an Outlook Folder
To specify the AutoArchive options for an Outlook folder:
- Click on the folder with the right mouse button in the folder list.
- Select Properties from the context menu.
- Go to the AutoArchive tab.
- Make sure Clean out items older than is checked.
- Specify how old items must be to qualify for automatic archiving.
- Click OK.