The links under the Techniques to Reduce Email heading of this page will inform the user how to go about removing email from the server to create more available disk space. The user should follow the link that corresponds to their computer platform and email application.
Some clients have an option to "Move email to Trash", "Mark email for deletion," or "Delete message immediately." If your email client is configured to "Move email to Trash" or "Mark email for deletion", an additional step is required to remove the message from the mail server. Until then the email would still be recoverable and not permanently deleted. (Since it is still in one of your mail folders it is still counted toward your quota.) For instructions on permanently deleting these messages, please view the appropriate link under Techniques to Reduce Email below.
The user may also wish to backup their email folder off of their local hard drive. Follow the appropriate link under Techniques to Backup Email heading for instructions on creating a backup copy. Unfortunately, backing up email using Web Mail and MyUH Email is not possible.
ref: http://www.hawaii.edu/itsdocs/quota/
