Our plugin uses the Action Scheduler Library to send the abandoned cart reminder emails automatically. This will reduce the dependency on the WP Cron and this does not require a special setup. The email sending is done every 15 minutes. If you want, you can change this interval from the "Run Automated Scheduler after X minutes" under the "Setting for sending Emails & SMS using Action Scheduler" section in the Settings tab. 

You can check out more about the Action Scheduler here.