How to Reduce Outlook Message Sizeby Joshua Laud
If you use Microsoft Outlook to download email and you use the program a lot, you may notice the Outlook message sizes increase dramatically. This happens when you store too many emails on your computer. There are various things that you can do in Microsoft Outlook to reduce the size of the mailbox.
Click "Start," then "All Programs," then "Microsoft Outlook."
Click "Tools," then "Mailbox Cleanup."
Click "AutoArchive" to start archiving emails automatically; this reduces the number of emails that will be stored in your main mailbox. Click "View Deleted Items Size" and change the number of MB that you want to store in the deleted items.
Click "Empty" to empty all of the deleted items. Click "Mailbox Cleanup" to clean up the whole mailbox.
Click "File," then "Data File Management." Click "Settings" and then "Compact Now." This compacts the entire mailbox.