> >(5) Messages sent to all-request should contain the list name so that > >bounces can be identified with the list whose owner they are for. > > Since people often own multiple lists, duplicates are eliminated before > the message is sent. So, there isn't a one to one mapping between owners > and lists. Another problem is that all-request typically reaches a whole > bunch of people. If each message needs to contain the list name, you may > end up with a lot of small individual messages with a handful of > recipients each, which take a lot longer to deliver. Each copy of the message could be tagged with the names of all the lists that a person owns. I understand that a lot more copies of the message would be generated, but I don't see that as a major problem, since all-request isn't used very often. Another way to handle the problem would be to have a command that tells what lists have a particular email address in their header. This would not be quite as effective because the mail might have been forwarded before bouncing.