I stand corrected, everything to the left of the "@" sign is case sensitive. It makes perfect sense if you think about it, which I should have done before I posted. :) On UN*X systems, the usernames jimj, JIMJ, JimJ etc... are all unique. The hostnames, meaning everything to the right of the "@" sign are not case sensitive. The info on the effects of not registering an ":internet" tag is still accurate however. I've appended some commands, and LISTSERV's reponses to demonstrate what I was describing in my previous note. It may not be the source of the problem we're discussing in this this thread, but I thought it still might help someone on the list. I'd definitely advise anyone on a Bitnet machine to register their Internet host name. To understand what the following commands illustrate, note that the BITEARN NODES entry for JHUVM includes a :internet.JHUVM.HCF.JHU.EDU tag. That's why the "DEL" command found and removed the subscriber on the list using the Internet host name. -jj ---- tell listserv quiet add jhtest-1 [log in to unmask] Test User Ready; T=0.04/0.07 00:17:46 * [log in to unmask] has been added to list JHTEST-1. * Notification has NOT been sent to Test User tell listserv quiet del jhtest-1 testuser@umbc2 Ready; T=0.03/0.07 00:18:11 * TESTUSER@UMBC2 does not appear in list JHTEST-1. tell listserv quiet del jhtest-1 [log in to unmask] Ready; T=0.03/0.07 00:18:22 * [log in to unmask] has been removed from list JHTEST-1. * Notification has NOT been sent to [log in to unmask] tell listserv quiet add jhtest-1 [log in to unmask] Test User Ready; T=0.04/0.07 00:18:42 * [log in to unmask] has been added to list JHTEST-1. * Notification has NOT been sent to Test User tell listserv quiet del jhtest-1 testuser@jhuvm Ready; T=0.03/0.07 00:18:51 * [log in to unmask] has been removed from list JHTEST-1. * Notification has NOT been sent to [log in to unmask]