MailChimp has set up a 2-step sign up as default:
First, users have to enter their emails in the newsletter sign up.
Then, they receive and email to confirm their subscription.
This is the standard set up, but we have now added an option if you want a direct sign up that bypasses that double step, it's as simple as checking a box.
1) Go to the Newsletter link on the hamburger menu.
2) The first checkbox you'll see is the one you'll want to check: "Bypass confirmation email and subscribe users directly."
3) Once you select that, just remember to click 'Save' and that's it!