MH is a modular mail system comprised of a set of shell-level commands.
The MH commands permit you not only to handle your mail in the usual way, e.g. to read messages, to produce scan summaries, and to reply to messages, but also to cobble together your own mail handling utilities by invoking MH commands from shell scripts or perl programs.
Here are two handy papers, supplied with the MH software distribution,
that you should seek out and read if you're unfamiliar with MH:
...And here are two useful books that cover MH:
Peek's book, as of the 1992 edition, doesn't cover MH's MIME facilities, although it's a good reference book for MH users. Rose's book isn't specifically about MH, but does include a lengthy discussion of MH's MIME facilities.
See appendix for information about how to
obtain the papers. See appendix
for ISBN
information for the books.