> Now I'm interested in the emails cron sends.  Currently in /etc/crontab
> there is:
> 
> SHELL=/bin/sh
> PATH=/usr/bin:/usr/sbin:/sbin:/bin:/usr/lib/news/bin

This in any case find your shutdown program.

> MAILTO=root
> #
> # check scripts in cron.hourly, cron.daily, cron.weekly, and cron.monthly
> #
> -*/15 * * * *   root  test -x /usr/lib/cron/run-crons &&
> /usr/lib/cron/run-crons >/dev/null 2>&1
> 
> so mail is going to "root".  How/where do I set up emails to go to some
> external email address? Presumably more than changing MAILTO= is
> required

No.

> - an smtp server needs to be specified somewhere?

No. Cron (as all other programs with the exception of your GUI email
clients) submits mail to your local MTA (mail transfer agent). It is
then your MTA's job to deliver any mail to worldwide.net. That's the
point of an MTA, and that's why it's a good idea to always configure it.
Submission to your local MTA can be by methods:

1) Calling /usr/bin/sendmail (or whereever located, for any good MTAs
compatible with decades old Unix practice), note this doesn't meaning
running the sendmail MTA. This is most common.

2) Delivering to localhost:25 via SMTP. fetchmail does this by default.

3) Delivering to hostname:25 via SMTP, if the MTA is configured to
listen on this external interface.

Linux systems currently ship with MTAs running after boot, and
configured to deliver mail at least on the local host. You need this
because too many Unix system programs communicate with email. Whether by
default systems ship with delivering mail only to localhost, or also to
worldwide.net, is distro dependent. SUSE goes worldwide, Debian as far
as I could see restricts to localhost (wish SUSE did too).

Also note that at least some Linux systems (includes SUSE) can easily be
configured to deliver mail sent to root to some other user instead. That
is because root shouldn't be reading mail (security risk with mail
clients), and the user reading root's mail should be the sysadmin (while
*not* logged in as root). In some cases having any mail delivered to
root is actually impossible, for example postfix refuses to run an MDA
(mail delivery agent, procmail!) as root in default config.

Volker

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Volker Kuhlmann                 is list0570 with the domain in header
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