I just tried to check about error messages on my list and received the strangest set of messages. The first indicated at a Rochester distribution point that the message had never gotten to the list site. In five minutes, I received the error messages for the post which according to the first message did not get to the site. The problem seems to be the mailer daemon or demon system. I understood this to be an automated gating system developped at Cornell, but it seems to be linked to a group of postmasters and network administrators who use the daemon software or designate themselves by this name. I always assumed that it checked the addresses. Could someone explain this system to me and why it is the major cause of my worst mailing problems?--Paul. -- Dr. Paul S. di Virgilio, University of Toronto [log in to unmask]