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 and Fidonet mail. The description language of the filters includes the standard operators or, and, not, near, their synonyms, and parentheses for defining the order of operators. The search can be executed on the whole word or on a part of a word.