Hey @Elisabeth as another API integration partner with Klaviyo, I think there’s an option from Channelize when they built the integration to bypass the double opt-in when people are joining through that integration. I’m not 100% positive, but that may be what’s going on.

Thank you Brett for your feedback. However I don’t want to bypass the double opt-in. I would like to make it work because this is mandatory for Europe.

Hi @Elisabeth, 

Thanks for chiming in here with your insight @Brett_Gatsby, very appreciated! @Elisabeth I would reach out to Channelize support to investigate how Channelize interacts with subscription/ opt-in data.

Thanks for participating in the Communtiy!

-Taylor 

@Elisabeth Did you find a solution?

I think the Jotform integration does the same thing. Registrations via JotForm are not triggering sending out the confirmation email for double opt-in.

I had to switch to single opt-in at the list level for new subscribes to be successful, but I would prefer double opt-in with a confirmation email sent out.