Having just switched a list from an IBM mainframe to a Windows NT version of listserv (also moving from 1.8a to 1.8c, now I'm seeing a new error message that I've never seen before....namely, "Host DNS for (server.name.blah) is misconfigured" along with what appears to be a standard template of stuff. Anyway, the list's size is around 1700 people. I'm seeing bounces from people I know who never had a problem with the old machine nor do they have a problem communicating directly with me. That said, a majority of people appear to be getting mail from the server just fine. But at least 100 different people have thrown the mmisconfigured DNS error message......too hard to believe that many different ones are messed up. So the question is: where do we look next? Is there something about the new installation that we need to focus on? Thanks, Ken Boschert, DVM Washington University [log in to unmask]