By default, double opt-in is enabled for all our customers’ accounts. This means that whenever a user fills in a subscription form / registration form, and you ask customers for explicit permission to subscribe them to promotional emails, this needs to be taken into account.

When a user checks that they want to receive promotional emails, you will need to make a call to our Add subscriber API, which will then send the double opt-in email for confirming the newsletter subscription.

If a user doesn’t check this option, they will still be captured in theMarketer platform via the __sm_set_email event, but they will not be subscribed to the newsletter.