> would you please explain the reasoning behind excluding the additional

> To: and Cc: recipients?



When I wrote LISTSERV in 1986, and I think this is still the case today, almost every discussion list had "Reply-To= List" and passing on the full header caused posters to receive a second copy of every response (and everyone who responded got a second copy of every further message in the thread). This drove people crazy because this second copy (1) came directly from Joe Random Subscriber's mail client and as such did not match any of the From: or subject tag rules you had set up in your mail client for the list, so it just landed in your main inbox instead of the folder you had set up for the list, and (2) tended to arrive first as it did not have to transit through LISTSERV, and as such it trumped the "real" list posting when it arrived a minute or so later with the same Message-ID:. So instead of having all the list conversation in the folder you had neatly set up for this purpose, you got a bunch of mail from people you did not know, in your main inbox and without any indication that it was from the list. This made people reluctant to participate actively because of the resulting inbox chaos. The most popular exploder on BITNET already rewrote headers for this reason and I decided to do the same.



Not much has changed with respect to this, although the net is so much faster that it can be a finish line shot between the direct and redistributed message. Nevertheless, as a subscriber to let's say this list, I appreciate receiving only one copy that predictably comes from the list and can be routed to the appropriate folder. There are cases where this is not the desired behavior, for instance because the purpose of the list implies that you often must cc: people who are not on the discussion list and must be included in every reply, and you can use IETFHDR then.



  Eric