How to stop cron from sending e-mail to pi@raspberrypi that causes delivery failure

This post is about how to stop cron from sending e-mail to pi@raspberrypi that causes delivery failure.

Fail message

Solution

Add a MAILTO = "" in crontab to stop cron from sending e-mail.

Reference:

https://www.raspberrypi.org/forums/viewtopic.php?t=66165&p=485288