Below are the steps to take to increase your Hosted Exchange Box limits.
Login at Customer Control Panel with your main account's username and password.
Click on the "Account" tab to the left of the "Help & Support" tab.
At the top right hand corner of the page you'll see a "Buy Additional Resources" link, click on it.
Check the button to the left of your Hosted Exchange Subscription and click the "Next" button.
You'll see the 2nd option from the top "Additional 1gb Storage", $2.95 X1GB / 1 Month".
Click the plus (+) sign to add the amount of space you want to buy to add to your account, then click the "Next" button.
Then click the "Place Order" button and the system will add the allotment to your account.
Now you will need to assign that space you've just purchased to your Hosted Exchange account.
Click on the "Exchange" tab at the top.
Select your account.
Click on the "Limits" tab.
At the bottom of the page, click on the "Edit" button.
(You'll need to set the "Issue Warning" at a size that will give you enough space to work with once you've been notified. So lets say you've just added another 1GB to your account, so you'll be able to increase your box limit to 3GB. We recommend setting your warning to something like 2.7GB. Take 1024 x 2.7 and that comes to 2764.8. Type that in the "Issue Warning at" section.)
Set the "Prohibit send" at and the Size Limit to 3GB (1024 x 3) which would be 3072 mb.
Then click the "Submit" button.
You've successfully increased your Hosted Exchange Box space limits.