diff --git a/Gemfile b/Gemfile
index 2815a8c..f0851c1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -44,6 +44,8 @@ gem 'rails_admin'
 
 gem 'mongoid_paranoia'
 
+gem 'mailchimp-api', require: 'mailchimp'
+
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug'
@@ -58,5 +60,5 @@ group :development do
   gem 'web-console', '~> 2.0'
 
   # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
-  gem 'spring'
+  # gem 'spring'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 71cea83..3acad52 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -67,6 +67,7 @@ GEM
     debug_inspector (0.0.2)
     diff-lcs (1.2.5)
     erubis (2.7.0)
+    excon (0.49.0)
     execjs (2.6.0)
     font-awesome-rails (4.6.1.0)
       railties (>= 3.2, < 5.1)
@@ -93,6 +94,9 @@ GEM
       nokogiri (>= 1.5.9)
     mail (2.6.4)
       mime-types (>= 1.16, < 4)
+    mailchimp-api (2.0.6)
+      excon (>= 0.16.0)
+      json (>= 1.7.7)
     method_source (0.8.2)
     mime-types (3.0)
       mime-types-data (~> 3.2015)
@@ -229,7 +233,6 @@ GEM
       railties (>= 3.1, < 5.0)
       slim (~> 3.0)
     slop (3.6.0)
-    spring (1.6.4)
     sprockets (3.5.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -266,6 +269,7 @@ DEPENDENCIES
   geocoder
   jbuilder (~> 2.0)
   jquery-rails
+  mailchimp-api
   mongoid (~> 5.0.0)
   mongoid-rspec (= 3.0.0)
   mongoid_paranoia
@@ -281,7 +285,6 @@ DEPENDENCIES
   simple_form
   slim
   slim-rails
-  spring
   turbolinks
   uglifier (>= 1.3.0)
   web-console (~> 2.0)
diff --git a/lib/mail_chimp_batch_update.rb b/lib/mail_chimp_batch_update.rb
new file mode 100644
index 0000000..11bea7d
--- /dev/null
+++ b/lib/mail_chimp_batch_update.rb
@@ -0,0 +1,25 @@
+class MailChimpBatchUpdate
+  def self.update_all(api_key, list_id)
+    subscribers = []
+    Supporter.each do |supporter|
+      subscriber = {
+        'EMAIL' => { 'email' => supporter.email },
+        'language' => supporter.language,
+        :EMAIL_TYPE => 'html',
+        :merge_vars => {
+          'EMAIL' => supporter.email,
+          'FNAME' => supporter.first_name,
+          'LNAME' => supporter.last_name,
+          'SUPPORT' => supporter.support,
+          'MEMBERSHIP' => supporter.li_membership.to_s,
+          'AGE' => supporter.age_category,
+          'LANG' => supporter.language
+        }
+      }
+      subscribers.push(subscriber)
+    end
+
+    mailchimp = Mailchimp::API.new(api_key)
+    mailchimp.lists.batch_subscribe(list_id, subscribers, false, true, false)
+  end
+end