Mailchimp stopped working

I cannot figure out why my Mailchimp integration stopped working with my site. My tests were working great. I don’t know what caused the change. I’ve triple-checked my Merge tags and link. The signups don’t receive an error message and it seems like the sign-up works. But Mailchimp audience list isn’t updated with the new subscriber.

Can you see the data which I just added?

Name: Marko
Last Name: Vukic

It seems that you have some issue with mails, it might be that your mails have been marked as spam and due to that not adding people to the list properly. It might be worth checking with mailchimp support

I finally figured it out. Someone selected double opt-in for Mailchimp that was preventing emails to be added to the list. Once I turned double opt-in off everything started working. THanks for your help!