On Mon, 27 Mar 2000 11:39:02 -0500, Tom Rawson <[log in to unmask]> wrote: >What's going on here? Why do some messages to these folks get through >whereas others apparently don't? You did not give the real domain name so I couldn't check. Many smaller or private domains hosted by ISPs will have 2 mail receivers (MX records) a Primary and a Secondary. The way the mail system works is that the Primary will be tried first but if connection cannot be achieved or the mail cannot be delivered then the Secondary site will be tried. The job of the Secondary sitge is to receive mail for the Primary and then either route the mail to the primary or hold it until the primary can be reached. The problem is that many sites, in their rush to cut down on spam or whose mail system admins are not adequately experienced, have incorrectly configured the secondary MX receiver so that it simply rejects the mail it should be accepting. This means that contrary to the MX records, there is no functioning secondary receiver. This is a site configuration problem, not really a LISTSERV issue, except that LISTSERV encounters this problem when sending out mail.