Some local laws require that your email subscribers opt-in to your email list, then confirm their subscription by clicking a link in their email, also known as a "Double Opt-in."
You can require double opt-in on your webforms.
Go to: Left Side Menu > Settings > Email Capture Forms
Add a new Email Capture Form, or Edit an existing one.
About half way down the page, you'll find a checkbox to turn on/off Double Opt-in.
When you turn it on, you'll need to add an email that will go out when they subscribe by entering it below the on/off checkbox.
That's it!
Now, anyone who fills out that form will have to confirm their subscription by clicking a link in their email.
IMPORTANT NOTE: In your email template, you will need to make sure there is a MERGE TAG added for the link to be created when it's sent to them. The merge tag is: {DOUBLE-OPTIN-LINK} and MUST be added exactly to work properly. We always recommend you test prior to going live with your webform.