Outlook 2003 AutoArchive
For starters, you can configure AutoArchive to archive your email according to your own preferences. On the Tools pull-down menu, click Options. In the Options dialog box, click the Other tab and the AutoArchive button. When you click the Run AutoArchive every x days check box, you can set Outlook to AutoArchive old emails at your preferred intervals and select from a number of other options. When you’re finished, click Apply These Settings To All Folders Now.
If you want to apply certain AutoArchive settings to individual folders, click Folder List from the Go pull-down menu. Right-click the folder you want and click Properties. In the folder’s Properties dialog box, click the AutoArchive tab, specify the settings you want, click Apply, and OK.

You can also archive your folders manually. On the File pull-down menu, click Archive. Indicate whether you want Outlook to archive all folders according to your AutoArchive settings or whether you want to archive a specific folder and click OK.
