Any further updates on this?
No, and there will not be. We have provided you a complete and responsive answer. Whether or not you undertake YOUR part of the response (that is, DO THE RESEARCH IN OUTLOOK) is not our concern. We have told you that flagging is a part of the email client and hence if
it is possible, you will have to find out how through your email client. z/OS will NOT be involved in the flagging, except possibly by sending some character.
Topic is being locked to prevent any further useless inquiries.