Why doesn't the list command work in mail?

Why doesn't the list command work in mail? When I try l or list, it doesn't work. It instead gives me a list of the valid commands, including list. Commands are: next, alias, print, type, Type, Print, visual, top, touch, preserve, delete, dp, dt, undelete, unset, mail, mbox, more, page, More, Page, unread, U, !, copy, chdir, cd, save, source, set, shell, version, group, write, from, file, folder, folders, ?, z, headers, help, =, Reply, Respond, reply, respond, edit, echo, quit, list, xit, exit, size, hold, if, else, endif, alternates, ignore, discard, retain, saveignore, savediscard, saveretain, core, #, clobber **Edit:** # cat /etc/redhat-release CentOS release 5.5 (Final) # mail --version mail: invalid option -- - Usage: mail [-iInv] [-s subject] [-c cc-addr] [-b bcc-addr] to-addr ... [-- sendmail-options ...] mail [-iInNv] -f [name] mail [-iInNv] [-u user] # $ rpm -qf $(which mail) mailx-8.1.1-44.2.2 Granted, I've NEVER been able to get this to work regardless of which distro. But I'll be happy to know how to do it on just one.