Hi folks- Please pardon what to most of you is probably a pretty basic question, but I am receieving regular delivery failure notices (error 550: user unknown) for a user who I cannot find in a regular REVIEW command. I have already tried to DEL this user, but listserv says he isn't a subscriber (I can't find even a significant substring of his address in the REVIEW output). How can I check what CONCEALED users are on my list? Thanks. George Buckner, co-owner, [log in to unmask]