[InterNetNews/inn] c11708: Add Auto-Submitted header field in outgoing mails

[Julien ÉLIE]

  Branch: refs/heads/main
  Home:   https://github.com/InterNetNews/inn
  Commit: c11708898b5a775bc319cd51f0a05914844f9792
      https://github.com/InterNetNews/inn/commit/c11708898b5a775bc319cd51f0a05914844f9792
  Author: Julien ÉLIE <Julien-Elie at users.noreply.github.com>
  Date:   2023-01-23 (Mon, 23 Jan 2023)

  Changed paths:
    M backends/news2mail.in
    M backends/sendinpaths.in
    M control/controlchan.in
    M doc/pod/inn.conf.pod
    M doc/pod/innmail.pod
    M doc/pod/news.pod
    M doc/pod/newsfeeds.pod
    M expire/expirerm.in
    M frontends/mailpost.in
    M nnrpd/post.c
    M scripts/innmail.in
    M scripts/innwatch.in
    M scripts/news.daily.in
    M scripts/rc.news.in
    M scripts/writelog.in

  Log Message:
  -----------
  Add Auto-Submitted header field in outgoing mails

Added a new "-a" option to innmail to specify additional header fields
to add in the headers of messages.  This is notably used to internally
support the addition of the Auto-Submitted header field in outgoing
mails.

All the programs sending mails now include an Auto-Submitted header
field in the message headers (either set to "auto-generated" or
"auto-replied", following the recommendation in RFC 3834):

- Daily Usenet reports (news.daily);

- newgroup/rmgroup/checkgroups reports (controlchan);

- top1000 reports (sendinpaths);

- failure or warning reports from various programs (mailpost, expirerm,
rc.news, innwatch, writelog);

- our internal wrapper to sendmail or like (innmail);

- gatewaying (news2mail);

- forwarding to a moderator (nnrpd).

Thanks to Harald Dunkel for this suggestion which will for instance
help to avoid unnecessary vacation replies.

close #255