What are Opt-in settings

In email marketing, the term Opt-in is used to express the permission given by a customer or a recipient of a mail, email, or other direct messages in order for you to send them merchandise, information, or more messages. 

We call Opt-in settings the procedure that you choose to follow when adding a subscriber to your email marketing list, depending on whether the member's confirmed consent is requested or not. 

You can select one of the following Opt-in types: Single Opt-in, Soft Double Opt-in, and Strong Double Opt-in.