Which single header in an email item consistently informs the reader (or software) that the item is from a mailing list, and lists the address (and name) of that mailing list? And in such a way that it is clearly NOT mail from a *person*. In the BITnet world the "Sender:" header was used for this purpose, which doesn't seem to be correct in the Internet world... BTW, I get confused by terminology like "mirrors", "exploders", etc., so if you include such, an explanation would be greatly appreciated (in plain English please?). Regards, and thanks in advance. $$\