Cron Job Email Notifications With sSMTP

Introduction

In this tutorial you will learn how to set up sSMTP in order to receive email notifications from your server. This makes it possible to get the output of a cron job via email.

Prerequisites

• An email account that will send the emails.

Step 1 - Install sSMTP

Connect to your server via SSH, and install sSMTP. You can do that by running:

apt update
apt install ssmtp

Step 2 - Update the sSMTP Configuration

The configuration files of sSMTP can be found under /etc/ssmtp.

Adjust settings in the /etc/ssmtp/ssmtp.conf file. When you are done, it should look like this:

MailHub=<smtp.example.com:465>
AuthUser=<cron-sender@example.com>
AuthPass=<cron-sender password>
UseTLS=YES
FromLineOverride=YES

Step 3 - Setup a Cron Job

Now you can setup a cron job with crontab -e. Before your cron jobs, you have to add MAILTO=<my-address@example.com> and MAILFROM=<cron-sender@example.com>.

MAILTO=<my-address@example.com>
MAILFROM=<cron-sender@example.com>
* * * * * echo 'Hello from cron'

Now you will get an email whenever a cron job runs.

Step 4 - Exclude a Cron Job from Sending Email

If you don't want a cron job to send emails, you can simply add >/dev/null 2>&1 at the end. This will redirect both stdout and stderr of that job to /dev/null and no email will be sent.

MAILTO=<my-address@example.com>
MAILFROM=<cron-sender@example.com>
* * * * * echo 'This text will be sent to /dev/null' >/dev/null 2>&1

Conclusion

With sSMTP configured on your server, you will now get emails for every cron job. This can be super helpful for example if you are auto upgrading some services on your machine. However, it can also be annoying. If you have a cron job that runs every minute, for example, you will also get an email every minute, so make sure you carefully select which cron jobs will send emails.

License: MIT