Matt - I'm going to BCC: TUHS and move this to COFF - since while UNIX was certainly in the mix in all this, it was hardly first or the only place it happenned.

On Wed, Aug 14, 2024 at 2:59 PM segaloco via TUHS <tuhs@tuhs.org> wrote:
On Wednesday, August 14th, 2024 at 9:45 AM, Clem Cole <clemc@ccc.com> wrote:

>
> ...
> The issue came when people started using the mail system as a programmatic messaging scheme (i.e., fork: some_program | mail user) and other programs started to parse the output.
> ...

Mail as IPC...that's what I'm reading from that anyway...now that's an interesting concept.
It's kind of funny the history.  ARPANET gives us FTP as a way to exchange files.   So, people figure out how to hack the mailer to call FTP to send a file remotely and set up a submit a cron/batch submission, a.k.a RJE.  This is encouraged by DARPA because part of the justification of the ARAPNET was to be able to share resources, and this enables supercomputers of the day to be able to provide cycles to DARPA folks who might not have access to larger systems.   Also, remember, mailers were local to systems at that point.  


So someone gets the bright idea to hooker the mailer into this system -- copy the "mail file" and set up a remote job to mail it locally.  Let's just say this prioves to be a cool idea and the idea of intersystem email begins in the >>ARPANET<< community.

So the idea of taking it to the next level was not that far off.  The mailer transports started to offer (limited) features to access services. By the time of Kurt's "delivermail" but he added a feature, thinking it was system logs that allowed specific programs to be called.   In fact, it may have been invented elsewhere but before Eric would formalize "vacation" - Jim Kleckner and I hacked together a "awk" script to do that function on the UCB CAD 4.1 systems.  I showed it to Sam and a few other people, and I know it went from Cory to Evans fairly quickly.   Vacation(1) was written shortly there after to be a bit more flexible than our original script.



  Did that idea ever grow any significant legs?
I guess the word here is significant.  It certainly was used where it made sense.  In the CAD group, we had simulations that might run for a few days.   We used to call the mailer every so often to send status and sometimes do something like a checkpoint.  It lead to Sam writing syslogd, particularly after Joy created UNIX domain sockets.   But I can say we used it a number of places in systems oriented or long running code before syslogd as a scheme to log errors, deal with stuff. 

 
  I can't tell if the general concept is clever or systems abuse, in those days it seems like it could've gone either way.

I guess it sorta did survive in the form of automated systems today expecting specially formatted emails to trigger "stuff" to happen.
Exactly.