I use drush to execute cron on my Drupal sites. After upgrading drush from version 5 to version 8, I started receiving empty emails from cron each time drush was executed. Checked my cron entries and everything looked fine. Researched a whole bunch on the Internet. Couldn’t find much of anything about empty emails related to drush so I redirected the output to a log. Sure enough, even with the –quiet option, drush cron still outputs a blank line.