Visit [My Agency] tab
In the [Appointments] sub-tab, click on [Manage Appointment Types]
When adding or editing an appointment type, notice the "Client Appointment Reminders" drop-down in the blue rectangle.
There are 4 options:
No Reminders - no reminders will be sent
Email - only email reminders will be sent
SMS (Text) - only SMS reminders will be sent
Email & SMS - BOTH Email and SMS reminders will be sent.
Also, notice the box to enter a value for "Hours before their appointment", which determines when the reminder is sent out.
Now, let's go to a Case file... then the [Appointments] tab...
All Appointment Types send out the reminder based upon the settings as described above.
When adding a "Custom" Appointment, the reminder is sent ONLY at the initial entry of the appointment! Reminders are NOT sent a certain number of hours before the scheduled time.