mailnavigator is a mail and news client that contains some unique capabilities. it contains a system for retrieving information from the archives of most popular mail programs, including microsoft mail, news, outlook, and outlook express; netscape messenger; eudora; forte agent; pegasus mail; the bat; eserv; fidonet mail. the description language of the filters includes the standard operators: or, and, not, near, their synonyms, and parentheses.