message-archive-header

message-archive-header is a variable defined in `message.el'.
Its value is

"X-No-Archive: Yes
"

Documentation:
Header to insert when you don't want your article to be archived.
Archives (such as groups.google.com) respect this header.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 22.1 of Emacs.