The mutt mailer is something like elm, but I like it better. The mutt home page has information about getting the distribution and buiding and installing the program. As of this writing, the current release is 0.60. However, development is rapid and newer releases appear regularly.
Before you build mutt, check your mail spool directory to make sure the permissions are correct.
mutt builds pretty easily under MkLinux; the only complication I've found is the need to tell the configuration process where to find the ncurses private headers:
% configure --with-curses=/usr
Under older distributions (prior to 0.54), the configure script doesn't use --with-curses. Use the --with-cursesinclude option instead:
% configure --with-cursesinclude=/usr/include/ncurses
You can build mutt with slang rather than ncurses, if you like. The distribution is available at ftp://space.mit.edu/pub/davis/slang/. I configured and installed slang in /usr/local/lib and /usr/local/include as follows:
% configure --prefix=/usr/local
% make
% make install
Then the configuration command for mutt becomes:
% configure --with-slang=/usr/local