HCL Domino Ideas Portal
Welcome to the #dominoforever Product Ideas Forum! The place where you can submit product ideas and enhancement request. We encourage you to participate by voting on, commenting on, and creating new ideas. All new ideas will be evaluated by HCL Product Management & Engineering teams, and the next steps will be communicated. While not all submitted ideas will be executed upon, community feedback will play a key role in influencing which ideas are and when they will be implemented.
I guess you mean the field "$Mailer" which contains information about the client sending this message. Currently the only option I an think of is to use business partner tools that can modify the message on the router level.