From reading the LISTSERV documentation, I've know that LISTSERV has two built-in filters. It uses those to help prevent mail loops, and redirects list-destined mail matching the filters to the list owner. I understand one can modify the default behavior with the "Filter=" and "Safe=" keywords and a few other things. What I can't discover (in an hour of rooting through the documentation and our LISTSERV installation itself) is exactly what is used in the default filters. I assume that addresses such as "postmaster" and "mailer-daemon" are filtered out. What I'd like to know is (1) What exactly is the list of filtered addresses? (2) Where is that information kept? (3) What headers are used with the check -- just "From:", or that and "Reply-to:", or what? (4) Is the envelope information checked? If so, what parts of it are used? We're running LISTSERV 1.8d beta (no, we haven't upgraded yet :-) ) on A Sun Ultra-2 with Solaris 2.6. I didn't know whether LSTOWN-L or LSTSRV-L was more appropriate for my question; please feel free to redirect me if I'm in the wrong place. Joe -- Joseph H. Vilas [log in to unmask] 1-919-660-6902 Box 90132, Duke University, Durham, NC 27708-0132 When I hear the word "internet," I reach for my revolver.