Schedule email reminders. Enter your reminder, where you'd like to email the reminder to, and when you'd like the reminder to be sent.
The plugin uses WordPress cron scheduler (WP Cron) to periodically check for reminders to be sent. Unfortunately, WP Cron is not a real cron scheduler like the one found in Linux operating systems which can run commands and scripts on time. WP Cron depends on users visiting your web site in order to trigger WP Cron. This means that by default, reminders won't always get sent on the exact time you want. This is most noticeable on sites with very low traffic.
But, there is a way to work around this problem by leveraging real Linux cron instead. Find out how by reading this tutorial
Check in your spam folder. Sometimes, email messages are marked as spam by your email provider especially if this is the first time you've used the plugin.