You can change how often AutoArchive runs, where it stores archived items, and how long Outlook keeps items before archiving them.
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Click File > Options > Advanced.
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Under AutoArchive, click AutoArchive Settings.
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Click the Run AutoArchive every n days box and specify how often to run AutoArchive.
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Choose any other options you want, such as having Outlook delete old items instead of archiving them.
Change the AutoArchive settings for an individual folder
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In the Navigation Pane's folder list, right-click the folder you want to change, and click Properties.
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On the AutoArchive tab, choose the options you want.
Source: Microsoft