Mailing list not updating

Hi,

I created a cover page with a newsletter signup button. When setting it up, I selected as a storage "Squarespace email campaign>Mailing list>Default". I don't have a Plan with Squarespace email campaign but I just want to collet email address from visitors.

I put the page live/visible to public and asked friends in different areas to subscribe to the newsletter form and I cannot find their email address.. I didn't receive any email or it is not in the mailing list part of Squarespace...

Does anyone know what it could be?

Thanks for your help!!

Camille

The may not have clicked the double opt-in link.  Unfortunately it’s not possible to disable double opt-in. 
https://support.squarespace.com/hc/en-us/articles/360002109868-Getting-permission-to-send-marketing-emails#toc-use-double-opt-in

After clicking the opt-in link I am still not getting people to be added to our list. Has anyone solved this?