It's that time of year when people make resolutions to do things better, and one promise that I hear often is to clean up their Outlook mail folders. Fortunately, Outlook 2007 makes this easy with the Mailbox Cleanup tasks found on the Tools menu:
First, check to see how you're doing in terms of usage by clicking the View Mailbox Size button. This will show you where your biggest mail folders are and, if you're using Exchange, how much available server space you have left.
Use the Find items section to search for older mails and really big ones. Set your date range (180 days will put you back six months) or size (1000KB = 1MB) and look for any messages that you can prune. You might want to check whether your company has a retention policy. It's possible management will want you archive or delete mails that exceed a certain number of months or years, in which case your task is simplified.
If you click the AutoArchive button, Outlook will instantly begin archiving items older than six months. (note the lack of "..." on the button? That means there is no options dialog here.) If you want to select which AutoArchive options to apply, close the Mailbox Cleanup window and go to Tools, Options, Other and click the AutoArchive button there instead:
The Mailbox Cleanup dialog also includes convenient buttons to empty your Deleted Items folder and remove any alternate versions of e-mail items. Odds are that you don't have any of the latter. If you do, you can check for a Conflicts folder that would have been created in the event of an Exchange Server sync issue. Mine showed a very small amount of usage even though I had no Conflicts folder, so I left it alone.
This once-a-year clean up is just the beginning. Keep your Outlook mailboxes in shape all year long with my Inbox Bootcamp series: