IT Solutions Technology Blog

The MAILTO environment variable in cron allows you to specify an email address to receive output from your cron job

root@rpi-samba-01:~# crontab -l
…
MAILTO=josef.schuster@dpsolution.de
# * * * * * echo „eMail Check“

01 0-23 * * * `journalctl –output=short -S yesterday| tail -c 131072 > /var/log/syslog` && `scp /var/log/syslog root@192.168.1.171:/var/log/UrgentSyslogShort.rpi-samba-01`
05 0-23 * * * `tail -c 131072 /var/log/samba/log.smbd > /var/log/smbd.log` && `scp /var/log/smbd.log root@192.168.1.171:/var/log/UrgentSambaLogShort.rpi-samba-01`

root@rpi-samba-01:~#

By default cron jobs sends an email via the MAILTO variable only if the cron job generates output (stdout or stderr) if a script runs completely error free and silently cron sends no message at all by default

root@rpi-iot-jsho-rslsync-01:~# crontab -l
…
MAILTO=josef.schuster@dpsolution.de
# * * * * * echo „eMail Check“

35 01 * * * ( export RESTIC_PASSWORD_FILE=/root/.restic-pass ; date >> /var/log/restic.local.log && restic -r /mnt/USB-Stick check && restic -r /mnt/USB-Stick forget –keep-daily 7 –keep-weekly 4 –keep-monthly 6 –prune && date >> /var/log/restic.local.log ; ) >> /var/log/restic.local.log

35 02 * * * ( export RESTIC_PASSWORD_FILE=/root/.restic-pass ; date >> /var/log/restic.extern.log && restic -r /mnt/USB-Stick.extern check && restic -r /mnt/USB-Stick.extern forget –keep-daily 7 –keep-weekly 4 –keep-monthly 6 –prune && date >> /var/log/restic.extern.log ; ) >> /var/log/restic.extern.log

05 01-23/2 * * * ( export RESTIC_PASSWORD_FILE=/root/.restic-pass ; date >> /var/log/restic.local.log && restic -r /mnt/USB-Stick backup /resilio-sync.data/USB-Stick && date >> /var/log/restic.local.log ; ) >> /var/log/restic.local.log

05 00-22/2 * * * ( export RESTIC_PASSWORD_FILE=/root/.restic-pass ; date >> /var/log/restic.extern.log && restic -r /mnt/USB-Stick.extern backup /resilio-sync.data/USB-Stick && date >> /var/log/restic.extern.log ; ) >> /var/log/restic.extern.log

root@rpi-iot-jsho-rslsync-01:~#

root@js-ubuntu-26-04-01:~# apt-get update && apt-get install msmtp msmtp-mta mailutils -y

root@js-ubuntu-26-04-01:~# msmtp –version
msmtp version 1.8.32
Platform: x86_64-pc-linux-gnu
TLS/SSL library: GnuTLS
Authentication library: GNU SASL; oauthbearer and xoauth2: built-in
Supported authentication methods:
scram-sha-256-plus scram-sha-1-plus scram-sha-256 scram-sha-1 plain gssapi external oauthbearer cram-md5 digest-md5 login ntlm xoauth2
IDN support: enabled
NLS: enabled, LOCALEDIR is /usr/share/locale
Keyring support: Gnome
System configuration file name: /etc/msmtprc
User configuration file name: /root/.msmtprc

Copyright (C) 2025 Martin Lambers and others.
This is free software. You may redistribute copies of it under the terms of
the GNU General Public License <http://www.gnu.org/licenses/gpl.html>.
There is NO WARRANTY, to the extent permitted by law.

root@js-ubuntu-26-04-01:~#

root@js-ubuntu-26-04-01:~# vi /etc/msmtprc
# Default settings
defaults
auth on
tls on
tls_trust_file /etc/ssl/certs/ca-certificates.crt
logfile /var/log/msmtp.log

# Target SMTP Server
account default
host smtp.1und1.com
port 587
from josef.schuster@dpsolution.de
user josef.schuster@dpsolution.de
password <password>

root@js-ubuntu-26-04-01:~#

root@js-ubuntu-26-04-01:~# vi /etc/aliases
root: josef.schuster@dpsolution.de
default: josef.schuster@dpsolution.de

root@js-ubuntu-26-04-01:~#

root@js-ubuntu-26-04-01:~# vi /etc/mail.rc
set sendmail=“/usr/bin/msmtp -t“

root@js-ubuntu-26-04-01:~#

root@js-ubuntu-26-04-01:~# echo „Inhalt der Mail“ | mail -s „Betreff: Mail Check“ josef.schuster@dpsolution.de

root@js-ubuntu-26-04-01:~#

root@js-ubuntu-26-04-01:~# tail  /var/log/msmtp.log
Sep 17 21:25:02 host=smtp.1und1.com tls=on auth=on user=josef.schuster@dpsolution.de from=josef.schuster@dpsolution.de recipients=josef.schuster@dpsolution.de mailsize=243 smtpstatus=250 smtpmsg=’250 Requested mail action okay, completed: id=ID‘ exitcode=EX_OK

root@js-ubuntu-26-04-01:~#