Defines the subscription method used to add a contact to a group.
Enumeration Values
Value
Description
CONFIRMED_OPT_IN
New contacts receive a welcome message via email when they are added to the group. Despite the label used for this value, the contact does not need to confirm the subscription. A single opt-in subscription.
DOUBLE_OPT_IN
New contacts receive an invitation to join the group via email. The contact must accept the invitation before they are added to the group. A double opt-in subscription.
OPT_IN
New contacts are added to the group without notification.
