Our staff mailing list is setup as a bunch of sublists that match our organizational chart hierarchy. One special case is our HELPDESK, which is a part of our Information Services department. HELPDESK is a sublist of INFOSERV, but HELPDESK is also a sublist of TECHSTAF in order to get the latest technical info. Both the INFOSERV & TECHSTAF lists are sublists of STAFF: STAFF | | INFOSERV TECHSTAF | | HELPDESK Under LISTSERV 1.6, the HELPDESK list got two copies of any mail sent to STAFF (undesirable, but not a big problem). LISTSERV 1.7 now detects a duplicate mailing and sends a nastygram back to the sender. What's the right way to set this up? -david