This was once a HUGE battle on the beta group. Some people feared that email addresses inadvertently included via email top-posts would remain indefinitely in the group archive, thus violating current members' privacy with respect to future members. It was finally settled in favor of the spoofing (aka "figleafing") being a group option, but the option has not yet been implemented. It's on the trello list and some of us have been waiting more than a year for it. :)
J
