Sending/Viewing Confidential Email with Outlook Web App (OWA)

Outlook Web App (OWA) allows you to access Office 365/Exchange mailbox in web browsers. OWA supports confidential email in popular browsers on all desktop platforms (Windows, Max OS X and Linux).

Staff may find the links to OWA at Email homepage, or directly at the following URL:

(Note: In mobile devices, OWA provides limited support to confidential email. It cannot open encrypted MS Office document attachments in confidential email. In some Android devices, OWA even cannot view and reply to confidential email.)

How to send confidential email to staff?

  1. In OWA, click New.



  2. Add CityU recipient(s) with email addresses in @cityu.edu.hk domain.

  3. Include the keyword #classified (case insensitive) in the email Subject field.
    (Or you may select "..." in the top menu, select Set permissions and then select CityU - #classified email instead.)



  4. If MS Office documents (Word/Excel/PowerPoint/InfoPath/XPS) are attached, they will be automatically protected with the same restricted access permission even when they are downloaded/detached from the email. But PDF and image type (PNG/JPEG/GIF) attachments will not be protected if they are downloaded/detached from the email.

  5. If you would like to send confidential email as read-only (i.e. recipient(s) cannot print, edit, or forward the email), select "..." in the top menu, select Set permissions and then select CityU - Read-Only. (the label #classified is optional as all read-only email is encrypted by default)



  6. Click SEND.

How to send confidential email to students, alumni and external parties?

  1. In OWA, click New.



  2. Add recipient(s) outside @cityu.edu.hk domain.

  3. Include the keyword #external (case insensitive) in the email Subject field.
    (Detailed information on the use of #classified and #external keywords can be found here.)



  4. Note: Attachments are encrypted with the email, but they are not natively protected with restricted access permission (i.e. they will NOT be encrypted/protected if they are downloaded/detached from the email)

  5. Click SEND.

How to view confidential email?

When receiving confidential email with #external keyword, CityU email system will decrypt it automatically prior to delivering it to your mailbox. You can consider it as normal email (For external recipients to view/reply to confidential email with #external keyword, please refer to here.).

When you receive confidential email from internal senders, Outlook displays it with an icon

  1. Click the confidential mail item to view it.



  2. To open protected file with file name extension .ppdf/.pjpg/.ppng/.pgif/.ptxt/.pfile attached in the email, the Microsoft Rights Management (RMS) sharing application is required. Please visit here for details.

How to reply confidential email?

You can reply to confidential email as replying to normal email. Replied email is confidential as well.

Note: When receiving confidential email with #external keyword, CityU email system will decrypt it automatically prior to delivering it to your mailbox. To reply to this type of email with encryption, please make sure the keyword #external (case insensitive) is included in the email subject.

csc@cityu.edu.hk