When an Artist is not on sale, from the institution website, we allow the contact to subscribe for the artist.
After the internet user has subscribed, a waiting list for the Artist is displayed in the system (Contact > Waiting List). The operator can send an alert to the contact when the Artist is on sale.
If the option "Double opt-in" is enabled for the Ticket shop sale channel, contact will be receiving a confirmation email for the waiting list (at this stage, the state of waiting list is PENDING), and operator can only send the alert once contact has confirmed the subscription to the Artist (the state is updated to OPEN).
