EC2 instance sends mail for every succesful or failed cron job - how to stop that?

Question

We receive hundreds of mails every day from the cron deamon to root@company.com. How can I stop that? Those mails refer to custom cron jobs set up by us - as well as others set up by AWS.

The mail subject looks as follows:

Cron <www-data@ip-172-12-34-56> [ -x /usr/share/awstats/tools/update.sh ] && /usr/share/awstats/tools/date.sh

I read this is default behavior but I can't find a way to switch it off.

Neither crontab -l nor sudo crontab -l contains a MAILTO directive or anything other than regular cron job timings.

---

> cat vim /etc/crontab    cat: vim: No such file or directory
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user  command
17 *    * * *   root    cd / && run-parts --report /etc/cron.hourly
25 6    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
47 6    * * 7   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
52 6    1 * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )

Answer 1

You have a few options.

You can set a MAILTO="*address*" variable at the start of your crontab to specify an e-mail address other than root@ or send it to a non-existant e-mail account.

You can use output redirection, so you could send everything to /dev/null by adding >/dev/null 2>&1 to the end of your cron jobs.

Or you could use some combination of output redirection and only send errors to e-mail or to a log file, etc.

http://wiki.bash-hackers.org/syntax/redirection has some more examples on how you could use redirection.