To be able to use the Double Opt-In feature,
Navigate to Inone Settings > Email Settings and scroll down to the Double Opt-in section.
Check the Enable Double Opt-in settings box. Once you enable it, Double Opt-in will be required for all emails you send.
After marking the checkbox, you need to add a confirmation page URL. This is the page where users will land after clicking the double opt-in confirmation button in the email. The URL can be any link from your website or a dedicated landing page designed for the Double Opt-In confirmation. Here’s one example of what a confirmation landing page usually looks like:
If you don't want to create a dedicated landing page, you can alternatively set up your confirmation page scenario by creating a pop-up on your website via an OnSite campaign and greeting your double-opt-in users. You can state that page’s URL in the Confirmation Page URL section.
Finally, from Email settings, you must choose what level of opt-in your email campaigns will require to be sent out to users via the ‘Campaigns would have following default opt-in’ setting:
Single Opt-in: If you choose this option, it means all future campaigns will be sent to users who have either Single opt-in or Double opt-in on their profile.
Double Opt-in: If you choose this option, it means all future campaigns will only be sent to users who have Double opt-in on their profile. Single opt-in emails will not receive your campaigns.
Click Save to have your double opt-in preferences reflected in the InOne panel.