[Nmh-workers] How Does One Set mts.conf for msmtp as Sendmail?

[Martin G. McCormick]

This is a debian wheezy system running
nmh                                   1.5-release-0.2 using
exim4 called as sendmail. The idea is to use as small a chain
saw on the system as possible so that I don't break local jobs
that send mail, etc. The /etc/nmh/mts.conf file is the only
mts.conf file on the system and there is a line:

mts: sendmail that tells this host which method to use

On another discussion list, a person using an openbsd system 
added the following line

     sendmail: /home/username/.msmtp-envelope-from.sh

just above

mts: sendmail

        There is no counterpart to a file named
.msmtp-envelope-from.sh in my home directory plus I don't see
anything telling nmh that the sendmail you always knew is now
referring to msmtp. The way it has always been is that sendmail
is a link to exim4. It presently delivers mail according to how
exim4 is configured.

        The best outcome is one runs nmh as always and non-local
messages go through msmtp to a smtp mail server while local
messages still stay local.

        Many thanks in advance. This has been a real slog in
which it appears this should work but step-by-step details are
hard to find so far.

Martin McCormick