app/models/subscription.rb

@@ -23,7 +23,7 @@ class Subscription < ActiveRecord::Base

                     response = Rails.configuration.mailchimp.lists.subscribe({
              

                       id: list_id,
              

                       email: {email: email},
              

                -      double_optin: false,
              

                +      double_optin: false
              

                     })
              

                     response
              

                   end