[ocbug] Mailing list functional again

[N.J. Thomas]

* Scott Murphy <scott.murphy at arrow-eye.com> [2021-09-13 13:44:10-0400]:
> Not that there was a lot of traffic, but the list has been restored to
> functionality for anyone who had made attempts to use it.

This used to happen to me a lot, here's how I solved the "I touched
something and broke the mailing-list and didn't notice util someone
emailed me directly days/week/months later" problem:

    - for every GNU Mailman site install, I create a
      "foo-monitoring at foo.example.org" mailing list

    - turn on the "hidden" bit in Mailman so it doesn't show up in the
      listings in the web interface

    - using a user on a host that is separate from the host running
      Mailman and also is not part of my mail infrastructure (it's
      important that you are mailing from the outside, just like a
      normal user would), I setup a cronjob to mail the list every 30
      minutes

    - the mailing list only has one user, and this user forwards all the
      mail from this list to a host where the mails are dumped into an
      mbox in /tmp

    - I setup Nagio NRPE to make sure this file is newer than 30
      minutes or so, anything older generates a warning/alert

    - I setup a cronjob to clean up the mbox in /tmp after some time

This works perfectly and has alerted me everytime an OS/Postfix/Mailman
upgrade/configuration change breaks my lists.

hth,
Thomas