Thanks to Peter and Darren for confirming this - now we need to work up a solution.
For the specific application, it won't be a big deal if the new messages are there and available, but the old ones haven't yet been removed completely. Dave Instructions for managing your mailing list subscription are provided in the Listserv General Users Guide available at http://www.lsoft.com Archive: http://vm.akh-wien.ac.at/MQSeries.archive