How To Schedule Regular Email Reminders Using Cron Job

In this comprehensive guide, we will explore how to schedule regular email reminders using a cron job. This is a powerful functionality that can automate repetitive tasks, such as sending out regular email reminders to a group of people.

Understanding Cron Jobs

A cron job is a time-based job scheduler in Unix-like operating systems. Users can schedule jobs (commands or scripts) to run periodically at fixed times, dates, or intervals. The name “cron” comes from the Greek word for time, “chronos”.

Prerequisites

Before we begin, ensure that you have the ability to send emails from the terminal. If you’re unsure how to do this, you can refer to this post for instructions.

Step 1: Open the Crontab File

Start by opening the crontab entries using the crontab -e command. This command opens the crontab file where we will specify the details of the cron job.

Step 2: Add a New Cron Job

In the crontab file, add the following line:

0 0 * * 1,3,5 $HOME/scripts/send_email.sh >> $HOME/tmp/out 2>&1

Here’s what each part of this line means:

• 0 0 * * 1,3,5 specifies the schedule of the cron job. This particular pattern means the cron job will run at midnight (0 0) on Monday, Wednesday, and Friday (1,3,5).
• $HOME/scripts/send_email.sh is the path to the script that the cron job will execute. In this case, we’re pointing to a script named send_email.sh in the scripts directory of the current user’s home directory.
• >> $HOME/tmp/out 2>&1 redirects the output of the cron job to a log file. This is useful for troubleshooting if something goes wrong.

Step 3: Create the Email Script

Next, create the send_email.sh script with the following content:

#!/bin/bash

recipients="user0@domain.com user1@domain.com user2@domain.com"
subject="...Subject..."

cat $HOME/email_message | mail -s $subject $recipients

In this script:

• recipients is a variable that holds the email addresses of the people you want to send the email to. Replace user0@domain.com user1@domain.com user2@domain.com with the actual email addresses.
• subject is a variable that holds the subject of the email. Replace ...Subject... with your desired subject.
• cat $HOME/email_message | mail -s $subject $recipients is the command that sends the email. It reads the message from the file $HOME/email_message and sends it to the recipients with the specified subject.

Step 4: Grant Execute Access to the Script

Finally, grant execute access to the script by running the following command:

chmod +x $HOME/scripts/send_email.sh

This command changes the permissions of the send_email.sh file to allow it to be executed.

Conclusion

And that’s it! You’ve now set up a cron job to send regular email reminders. Remember to replace the email addresses, subject, and email message with your own values.

If you encounter any issues, you can check the log file at $HOME/tmp/out for any error messages. And if the method above doesn’t work for you, an alternative solution is to use the sendEmail tool. You can find more information about it here.