Two appointment reminder calls at the same time

What happens if 2 different appointments are scheduled at the same time, and both are set to make a reminder call for 1 day before the appointment, and you only have a 1 line license? Will it still make a reminder call for both appointments, just one after the other, or will 1 be lost?

Yes, Voicent AutoReminder will make both calls even though you have only one line.

There is a built-in outbound call scheduler. If there is a conflict, one call will be rescheduled for later time when the line is freed. For appointment reminder calls, the latest time a reminder call will be rescheduled is the appointment start time. In your case, if you scheduled the call 1 day before, you have plenty of time for the call to go out.