I seem to recall mentioning to you at least once that in order to stop this rewriting you need to make listserv.temple.edu an A record instead of a CNAME. Any sendmail that doesn't have canonicalisation turned off (and that's most of them) is going to rewrite a CNAME every time as the mail passes through it. >Also, how does Listserv deal with environment varialbles passed to >Listserv? What do you mean? LISTSERV's configuration is passed in the form of environment variables but that is the only way I know of to pass that kind of information to the server. Feel free to amplify. Nathan