You might want to cancel older messages that are out of date. When you cancel a message that has already been uploaded, its status will change to canceled and it will move to the mailbox's Canceled tab.
Note: You may still download a message from a mailbox even after it has been canceled.
This section describes how to cancel messages in various states:
Cancel available messages in a mailbox before they are downloaded
Cancel messages you sent (uploaded)
Cancel upload or download transfers that are still in progress