There are a few things you can do to help manage your Outlook mail size. First, make sure you have the correct settings for your account. If you don’t have a password, set one up. Second, make sure you’re using the most recent version of Outlook. Third, try to keep your mailbox empty as much as possible. Finally, use the “Organize by” feature in Outlook to group all of your messages into one place.
Using Mailbox Cleanup
With Outlook open, go to Tools Mailbox Cleanup.
Now with the Mailbox Cleanup dialog box open click on View Mailbox Size. You can also use this same dialog to easily find old email, or items that are larger than a certain size, so you can delete them and reclaim some space.
In the Folder Size dialog will show the amount of space being taken up on your local machine by each folder. If you are on an Exchange Server just click on the Server Data tab to find out how much space is being taken up on the server.
Depending on the size and your setup you might want to Easily Compact The Outlook Data File.
