Double opt-in signup
This is recommended at the first contact, especially for newsletter sign-ups. This way you can make sure that the customer is giving a valid email address.
After submitting a form, the customer gets a confirmation email in which the Other: Email activation link variable has to be inserted. When the customer clicks on the link, her email address becomes active but until then it will have a waiting for activation status in MiniCRM.
The customer is sent a confirmation email of the double opt-in after clicking the link and is sent to the page you specify in the Thank you page URL.