There are two ways you can use double opt-in inside a workflow:
1. Auto send double opt-in during enrolment
Once you’ve selected an enrolment type and begun your workflow, there is a checkbox that allows you to check a contact's opt-In status before allowing them to continue through the workflow.
When the box is ticked a double opt-in email will be sent to contacts matching the criteria automatically, and contacts will be held inside this node until they confirm their subscription.
The double opt-in email will be sent out to any contacts that are NOT already double opt-in verified including double opt-ins, single opt-ins, and unknown opt-ins.
2. Send a double opt-in email using a campaign node
If you add a Campaign Node to your workflow, there is the option to send out a double-opt-in Campaign.
To do this, select the ‘Advanced’ option inside the Campaign Node and then check the ‘Auto Send Double Opt-In Email’ box.
If you want to send a follow-up email to contacts once they have opted in, use the Campaign node again and select your chosen campaign.