Adding this new feature
You really should consider developing / adding a "SMS" feature to the CRM that is tied (as an option) to the calendar.
Once an appointment is placed on the calendar, there could be a box that reads something like, "Enable SMS". When clicked you could choose how often you want your (pre-personalized)text message to be sent that automatically includes the date & time scheduled. The message would then give the recipient the option to confirm, cancel, help or stop. This would take additional steps off what the Admins have to do in order to send / call with reminders to improve appointments kept & increase revenue for Redtail. Why should the other guys earn money from your customers? Thank you!