As described by Creating Bookings, when a booking is made, the user can choose to enable booking reminders. For each user, their User Settings specifies the default values for booking reminders. The global preference for booking reminders is similar, but allows an administrator to specify the booking reminder user settings for newly registered users. The global setting is used only for setting up new users and nothing else.

 

cal_GenPrefBookingRem

Choose who gets a reminder email, with the options being:

The person that made the booking

The person that owns the booking

The person that owns the booking's project. If there is no project on the booking, then this setting is ignored.

The people associated with the booking's project. If there is no project on the booking, then this setting is ignored.

 

If one person falls into more than one category, for example the project owner is also the person that made the booking, they will only receive one reminder email.