Exmh is a TCL/TK based interface to the MH (a.k.a. nmh) mail system.
Exmh provides a graphical frontend to most MH features, including
reading, deleting, and refiling messages. In addition, the interface
handles arbitrary nesting of your folder hierarchy. Its extensibility
allows Exmh to interoperate with PGP, Glimpse, ispell, faces/picons,
MIME, and much more.