How Can I connect Mail Chimp And Kleo ?

Hello,
I’m Started with Gravity Forms.
I would like than users have to put his E-Mail in MailChimp to download a digital Files.
I chosse MailChimp only for send Mail to All Users ( i think than we can’t make that with BuddyPress ? ).
I saw than we can make a pop up for all user but no to send a Mail.

The Best will be than an user connect with his EMail already in MailChimp can download directly his Files.
I would like too than a Users can choose Subscribe in NewsLetter when he’s making his account in my kleo WebSite.
Do you know a good Way to Do That ( MailChimp and GravityForm will be good to do that ? You know some Good “Add On” or best Plugins ? )

Thanks You 🙂

Thanks you