With Teamup, you can enable signups for any event (or by default for all events on the calendar). Anyone with access to the calendar event can then sign up with their name and email address. If someone includes their email address when they signup for an event, they will automatically receive a confirmation email.
Our latest update makes it possible for the calendar administrator to control whether confirmation emails are sent for event signups. By default, confirmation emails are enabled.
This is a global switch that applies to all signups. Turning this option on or off will apply to all signups for all events.