LISTSERV already has in place the vehicle you need.  The list
owner can  set the  Ack keyword  to either Yes,  No, or  Msg, and
indivuals  on  the  list  can set  their  preference  by  TELLing
LISTSERV  to SET  ACK  YES or  NO or  MSG.   "Yes" requests  full
acknowledgements, and  is the default.  "No"  currently sends one
interactive  message   saying  "Your  mail  for   ...   has  been
successfully  processed.", but  it has  been suggested  that even
that  is  too much.   "Msg"  causes  the  stats  to be  sent  via
interactive messages instead of as a mail file.
 
    The only  thing missing  is a  way to set  the Ack  value for
senders who are not also  receivers (although changing the list's
value would  probably do the  trick at  the expense of  those who
haven't made up their minds.)
 
Ross