One of the very helpful folks who privately emailed me solutions to my
disabillity happened to hit the nail on the head: the suggestion was made
to use the 'h' command in elm to reveal the hidden headers.
 
Now, in the novice (starter-default) menu for elm, there is no hint that
such a command exists.  The headers one does see take up half a screen,
and how shall the unwary know there's more?  Further, the 'h' command when
struck once, simply flashes the successive headers, about
half-a-secondeach, on the first line of the screen before laying out the
stable message.  It's only on the third or fourth frustrated smack that
everything goes as it should: an lo and behold, there's the 'From' line
with an address that I can write down and then enter manually to send
private mail.
 
Elm is a widely-used mailsystem.  The information I would have needed
doesn't appear in the manuals I've been given (on two systems now).  The
computer experts at the info lines didn't have a clue.  PLEASE, all you
wizards, try to remember how it was before you knew all that good stuff?
 
I, too, have an esoteric field of my own: to me, the computer network is a
lovely toy and useful tool.  I'm trying hard to learn what I need to.
 
Thanks, especially to all those who sent helpful and gentle suggestions.
 
--bayla