You can modify the amount of disk space allocated to any email address.       The amount allocated is represented in megabytes.
Steps
- Find the email account you want to use to change the disk quota in         the "Current Accounts" table.
- Select the Change Quota option from the drop down         menu in the "Functions" column.
- Enter the amount in megabytes in the "New Quota" text box.
- Click on the Change button.
- A confirmation statement will be shown:         
- "The e-mail account EMAIL_ACCOUNT was successfully modified."
 
- Click on the Go Back button.
- When the page loads, the disk quota you modified will be displayed         in the "Quota" column in the "Current Accounts" table.