Saving Space

Keeping Under Quota
While the Exchange administrators would like to be able to accommodate requests to increase the limits in place for mailbox size, enforcing the 100MB quota per mailbox is critical to maintaining the health of the Exchange server. This quota limit ensures that we are able to reserve the required amount of disk space necessary to run maintenance utilities and keep the server performing well. Public Folders are located on another Exchange server, making an accurate projection of the growth of the Private Information Store (mailboxes) size possible.
The best way to keep your mailbox under the quota is to practice good email management. Routinely monitor the number of messages in each of your folders. Delete messages not related to your work, unsolicited junk mail, messages that are no longer important. Delete the items in your Deleted Items folder. Delete or move attachments, as they are generally large and add substantially to the size of your mailbox.
Many staff members have legitimate reasons to retain a large number of messages, and a couple of options for reducing the size of mailboxes when they grow in excess of the 100MB limit are auto-archiving or creating personal folders. Both of these methods save selected messages to another location, yet they are available for viewing when there is access to the saved location.

General Practices
Along with the tips above, try to make it a habit of consolidating and deleting / archiving any messages you are sure you will not need. This will keep your inbox and folders much neater and make life easier for you when using Outlook. Just like a clean car, if you stay up to date and keep things tidy every time you use it, you won’t run into nearly as many problems.