Pre-sales info – WooCommerce Coupon Box

Hello,
reference to “WooCommerce Coupon Box” plugin I’d like to know:

1) Which email API supports the “double opt-in” option? In the documentation I saw double opt-in is available in Mailchimp API only. In anyone else? For example in Sendinblue?

2) When I use the Mailchimp API with “double opt-in”, I expect the email with the coupon code to be sent to the subscriber only after the “double opt-in” process has been completed successfully. Do you confirm this?

Thanks.