On Sat, Jun 23, 2018 at 8:18 PM, Grant Taylor via TUHS <tuhs@minnie.tuhs.org> wrote:

What little I know about the MH type mail stores and associated utilities are indeed quite powerful.
Yep, their power and flaw all rolled together actually.     Until I had Pachyderm on Tru64/Alpha with AltaVista under the covers (which was gmail's predecessor), I ran a flavor of MH from the time Bruce (Borden - MH's author) first released it on the 6th edition on the Rand USENIX tape. ​  I'm going to guess for about 25 years.   Although for the last 8-10 years, I ran a post processor user interface called 'HM' (also from Rand) that was curses based that split the screen into two.


 
  I think they operate under the premise that each message is it's own file
​Correct - which is great, other than on small systems it chews up inodes and disk space which for v6 and v7 could be a problem.   ​But it means everything was always ASCII and easy to grok and any tool from an editor to macro processor could be inserted.   It also meant that unlike AT&T "mail", the division between the MUA and the MTA was first declared by the Rand and understood in Unix and used in the original UofI ArpaNet code (before Kurt's delivermail  [sendmail's predecessor] which was part of UCB Mail, or the MIT mailer ArpaNet hacks that would come later).

BTW: I may have the the original Rand MH release somewhere.  We ran it at Tektronix on V6 on the 11/60 and then V7 on the TekLabs 11/70, as I brought it with me.  We hacked the MTA portion to talk smtpd under Bruce's UNET code to our VMS/SMTPD at some point.

 
and that you work in something akin to a shell if not your actual OS shell.
​Exactly.   ​Your shell or emacs if you so desired - whatever your native system interface was.  HM took the idea a little further to make things more screen oriented and later versions of MH picked some of the HM stuff I'm told; but I had started to use Pachyderm - which was search based.

 
  I think the MH commands are quite literally unix command that can be called from the unix shell.  I think this is in the spirit of simply enhancing the shell to seem as if it has email abilities via the MH commands.  Use any traditional unix text processing utilities you want to manipulate email.
Absolutely.  I do find myself, pulling things out of gmail, sometimes so I can do Unix tricks to inbound mail that gmail will not let me do.   And when I want to do anything really automating on the send side, I have MH installed and it calls the local MTA.   But I admit, the indexing that search gives you is incredibly powerful for day to day use and I could not go back. to MH.