Please refer to the following procedure to access email protected using "Do Not Forward" in OWA (Outlook Web Access via webmail.hku.hk or MyEmail tab under HKU Portal).
Go to https://webmail.hku.hk.
Login with your HKU Portal UID and PIN. Then click Sign In.
For protected message,icon will be shown next to the message. Tap to open the message.
The protected message content will be displayed.
A Sample email proteced by "Do Not Forward"