This non nmh perl approach seems to work for me:
smtp-cli \
--verbose \
--host smtp.gmail.com:587 \
--user MYGOOGLE_USERNAME --password XXXXXX \
--auth \
--from MYGOOGLE_USERNAME@gmail.com \
--to SOMEONE@gmail.com \
--data /tmp/MSG_WITH_HEADERS_AND_BODY
I _think_ most of the information you want is in send(1), but here are
some likely switches you need to add to send:
-sasl
-server smtp.gmail.com
-user MYGOOGLE_USERNAME
-tls
You want to put the password in a .netrc file, or some other file defined
by the "credentials" profile entry. mh-profile(5) has this info, but
the entry in there should look something like:
machine smtp.gmail.com login MYGOOGLE_USERNAME password XXXXXX
You can use the -snoop switch to send(1) to see what is going on,
that will be invaluable for debugging. FYI, in my experience
"MYGOOGLE_USERNAME" includes "@gmail.com", but that is outside the scope
of nmh; it will happily use whatever you put in there, but you have to
get it right.
And if you don't mind me asking ... I would like to make this information
more easily findable. Were you just overwhelmed at where to start?
Did you look at send(1)? If you did, what was unclear?
--Ken