[Vladyslav Romashov]

Forget about this. Will move to another theme.

Thanks

[Vladyslav Romashov]

Thanks for the reply!

I have resolved it with other plugins. In case anyone else will stuck with the same problem, you can use:

When there is no checkbox needed
(1) Contact Form 7 + (2) Contact Form 7 Extension For Mailchimp

When you need people to use the checkbox
(1) Contact Form 7 + (2) MC4WP

Contact Form 7 has instant email reply where you can add attachments