It is possible to compile the win32 port of Mutt with DJGPP and that way create a DOS program. Since programs compiled with DJGPP uses a DOS extender, you need at least a 386 to run it. Besides that, even though Mutt is considered a small program today, it is huge by old DOS standards (640k is hardly enough).

You should probably try to find a mail client written directly for DOS instead.

Links:

Mutt DJGPP