Sign in to Web Mail using your email address and password.
Note: Your password is Case Sensitive.
In the upper-left corner of the page, view the amount of storage space you have.
Note: Each mailbox contains 100MB of storage space.
While looking down the Size column, find emails with a large size, then place a check in the boxes for those emails and click the Delete button at the top of the page.
Click the Trash folder on the left.
Click the Empty this folder link on the top right.