diff --git a/Gemfile b/Gemfile
index 232089fa0..9a171b5b6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -35,6 +35,7 @@ gem 'htmlentities'
 gem 'onebox'
 gem 'simple_form'
 gem 'will_paginate', '~> 3.0.6'
+gem 'rack-attack'
 
 group :development, :test do
   gem 'rspec-rails'
@@ -55,6 +56,7 @@ group :development do
   gem 'better_errors'
   gem 'binding_of_caller'
   gem 'rack-mini-profiler'
+  gem 'letter_opener'
 end
 
 group :production do
diff --git a/Gemfile.lock b/Gemfile.lock
index 1fd718c8e..adbf3e537 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -129,6 +129,10 @@ GEM
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
     json (1.8.3)
+    launchy (2.4.3)
+      addressable (~> 2.3)
+    letter_opener (1.4.1)
+      launchy (~> 2.2)
     libv8 (3.16.14.13)
     loofah (2.0.3)
       nokogiri (>= 1.5.9)
@@ -180,6 +184,8 @@ GEM
     rabl (0.12.0)
       activesupport (>= 2.3.14)
     rack (1.6.4)
+    rack-attack (4.4.1)
+      rack
     rack-mini-profiler (0.9.9.2)
       rack (>= 1.2.0)
     rack-test (0.6.3)
@@ -331,6 +337,7 @@ DEPENDENCIES
   http
   jbuilder (~> 2.0)
   jquery-rails
+  letter_opener
   nokogiri
   oj
   onebox
@@ -342,6 +349,7 @@ DEPENDENCIES
   puma
   quiet_assets
   rabl
+  rack-attack
   rack-mini-profiler
   rails (= 4.2.5.1)
   rails_12factor
diff --git a/config/application.rb b/config/application.rb
index e7634854a..9d8d6022d 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -33,5 +33,7 @@ module Mastodon
       Doorkeeper::AuthorizedApplicationsController.layout 'dashboard'
       Doorkeeper::AuthorizationsController.layout         'auth'
     end
+
+    config.middleware.use Rack::Attack
   end
 end
diff --git a/config/environments/development.rb b/config/environments/development.rb
index b55e2144b..76e52312d 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -38,4 +38,6 @@ Rails.application.configure do
 
   # Raises error for missing translations
   # config.action_view.raise_on_missing_translations = true
+
+  config.action_mailer.delivery_method = :letter_opener
 end
diff --git a/config/initializers/rack-attack.rb b/config/initializers/rack-attack.rb
new file mode 100644
index 000000000..fc2b56c87
--- /dev/null
+++ b/config/initializers/rack-attack.rb
@@ -0,0 +1,3 @@
+class Rack::Attack
+  # TODO
+end