According to the EU General Data Protection Regulation (EU GDPR), the explicit consent of the data subject is necessary for the processing of personal data. 
The double opt-in offers the opportunity to obtain such a declaration of consent.

Process

A form with double opt-in activated does not go through the status of received after being sent, as opposed to a regular form (see Status and action processing). Therefore the status and action processing is not yet triggered. 
Instead, an e-mail will be sent with a confirmation link. Only after this link is called the configured processing of the form begins. The confirmation link can only be called once and is then no longer valid. In this way, for example,
the consent of users can be obtained. The e-mail address is typically obtained from the form itself.

Setting

You can call up the configuration dialog for the Double opt-in via the corresponding button in the form menu. There are a number of required fields that are necessary for the implementation of the double opt-in.

Required fields

• e-mail to
  Indicates to whom the email should be sent with the confirmation link. Typically, the e-mail address is obtained via Platzhalter.

• e-mail from
  Specifies the sender address of the double opt-in mail.

• subject
  Specifies the subject of the double opt-in mail.

• message
  The message to be sent with the double opt-in mail. This should contain the confirmation link. The confirmation link is available via the Platzhalter [%$FORM_VERIFY_LINK%]. If the message is left blank, a standard message will be sent with the confirmation link.

Optional information

• sender name
  Specifies the name of the sender of the double opt-in mail.

• Answer page
  By default, the system templates for double opt-in are sent for the three cases  double opt-in email sent ,  double opt-in successfully completed  and  double opt-in failed. Via  Dateien & Templates > HTML in the menu you can create and design your own answer pages.

  • double opt-in email sent
    The page that appears after submitting the form and the double opt-in email.

  • double opt-in successful
    The page that is shown after clicking on the double opt-in link. 

  • double opt-in failed
    The page that appears when a double opt-in error has occurred. For example, when the double opt-in has already been confirmed.

•  Automatic deletion
  Datasets that have not been confirmed can be automatically deleted. If no time is specified, the data is saved permanently.