manitou-mdx and the associated script manitou-mgr come in a standard Perl source package that can be built and installed by these commands:
cd /path/to/manitou-mdx-x.y.z perl Makefile.PL make make install
To install in a non-system location /my/path, the invocation would be:
perl Makefile.PL DESTDIR=/my/path PREFIX=''
To configure for a pre-compiled package like those used in system distributions, the invocation would be:
perl Makefile.PL INSTALLDIRS=vendor
manitou is the program that provides the Mail User Agent functionality in a graphical user interface. It can be built for MS-Windows, Mac OS X and Unix operating systems. For detailed instructions on how to build manitou on different platforms, refer to the wiki.