How can I clean up the mailbox in Microsoft Office Outlook 2007?

The first option lets you manage the size of the mailbox. Clicking the View Mailbox Size button shows in kilobytes the individual folder sizes that comprise the mailbox's total volume. This information can help you identify where attention is most needed to reduce the amount of storage necessary for the account. If you’re close to exceeding your quota and you’re worried about not receiving future messages, moving or deleting large items will have the greatest immediate effect on mailbox size.

The second option provides a filtered search for content older than a certain date or larger than a certain size. A user can query his or her mailbox for items beyond a specified age in days or size in kilobytes. The returned query lists items that include many good candidates for archiving or deletion. Alternatively, you can create search folders in Outlook to dynamically provide such lists of items on an ongoing basis, so that you don't have to query the mailbox each time you need to obtain the list items that meet your age or size criteria. To create a search folder, from Outlook’s File menu, select New, Search Folder, and specify the age and message size.

The third option, AutoArchive, moves content from the mailbox or PST to a separate archive PST. The autoarchiving option in Outlook 2007 (as well as Outlook 2003 and Outlook 2000) still doesn’t provide a confirmation or configuration screen when you click it, but instead enters directly into an archiving session.

The fourth option lets you empty the deleted items folder. Clicking the View Deleted Items Size button tells you the size of the deleted items folder and any subfolders, in kilobytes.

The fifth configuration option is enabled only if you have conflicting versions of items. This option helps clean up the mailbox by letting you purge the duplicate versions of items—those that Outlook deems to bethe same, but in conflict.