diff --git a/Gemfile b/Gemfile
index 33a37e0..1bb5d3e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -31,6 +31,10 @@ gem 'js-routes'
 gem 'kaminari'
 gem 'ransack'
 gem 'responders'
+gem 'sidekiq', '~> 6.5.0'
+gem 'sidekiq-failures'
+gem 'sidekiq-throttled'
+gem 'sidekiq-unique-jobs'
 gem 'simple_form'
 gem 'slim-rails'
 gem 'state_machines-activerecord'
diff --git a/Gemfile.lock b/Gemfile.lock
index 5d8127e..c3a088f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -68,6 +68,9 @@ GEM
     bindex (0.8.1)
     bootsnap (1.15.0)
       msgpack (~> 1.2)
+    brpoplpush-redis_script (0.1.3)
+      concurrent-ruby (~> 1.0, >= 1.0.5)
+      redis (>= 1.0, < 6)
     builder (3.2.4)
     byebug (11.1.3)
     capybara (3.38.0)
@@ -83,6 +86,7 @@ GEM
       activesupport
     childprocess (4.1.0)
     concurrent-ruby (1.1.10)
+    connection_pool (2.3.0)
     crass (1.0.6)
     docile (1.4.0)
     erubi (1.11.0)
@@ -151,7 +155,7 @@ GEM
     puma (4.3.12)
       nio4r (~> 2.0)
     racc (1.6.0)
-    rack (2.2.4)
+    rack (2.2.5)
     rack-proxy (0.7.4)
       rack
     rack-test (2.0.2)
@@ -191,6 +195,8 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
+    redis (4.8.0)
+    redis-prescription (1.0.0)
     regexp_parser (2.6.1)
     responders (3.0.1)
       actionpack (>= 5.0)
@@ -225,6 +231,22 @@ GEM
       rexml (~> 3.2, >= 3.2.5)
       rubyzip (>= 1.2.2, < 3.0)
       websocket (~> 1.0)
+    sidekiq (6.5.8)
+      connection_pool (>= 2.2.5, < 3)
+      rack (~> 2.0)
+      redis (>= 4.5.0, < 5)
+    sidekiq-failures (1.0.4)
+      sidekiq (>= 4.0.0)
+    sidekiq-throttled (0.17.0)
+      concurrent-ruby
+      redis-prescription
+      sidekiq (>= 6.4)
+    sidekiq-unique-jobs (7.1.29)
+      brpoplpush-redis_script (> 0.1.1, <= 2.0.0)
+      concurrent-ruby (~> 1.0, >= 1.0.5)
+      redis (< 5.0)
+      sidekiq (>= 5.0, < 7.0)
+      thor (>= 0.20, < 3.0)
     simple_form (5.1.0)
       actionpack (>= 5.2)
       activemodel (>= 5.2)
@@ -309,6 +331,10 @@ DEPENDENCIES
   rubocop
   sass-rails (>= 6)
   selenium-webdriver
+  sidekiq (~> 6.5.0)
+  sidekiq-failures
+  sidekiq-throttled
+  sidekiq-unique-jobs
   simple_form
   simplecov
   slim-rails
diff --git a/app/controllers/api/v1/tasks_controller.rb b/app/controllers/api/v1/tasks_controller.rb
index df25aa7..fecd8e2 100644
--- a/app/controllers/api/v1/tasks_controller.rb
+++ b/app/controllers/api/v1/tasks_controller.rb
@@ -18,20 +18,21 @@ def index
   def create
     params['task']['author_id'] = current_user.id if params.dig('task', 'author_id').nil?
     task = current_user.my_tasks.new(task_params)
-    UserMailer.with({ user: current_user, task: task }).task_created.deliver_now if task.save
+    SendTaskCreateNotificationWorker.perform_async(task.id) if task.save
     respond_with(task, serializer: TaskSerializer, location: nil)
   end
 
   def update
     task = Task.find(params[:id])
-    UserMailer.with({ task: task }).task_updated.deliver_now if task.update(task_params)
+    SendTaskUpdateNotificationWorker.perform_async(task.id) if task.update(task_params)
 
     respond_with(task, serializer: TaskSerializer)
   end
 
   def destroy
     task = Task.find(params[:id])
-    UserMailer.with({ task: task }).task_deleted.deliver_now if task.destroy
+    SendTaskDeleteNotificationWorker.perform_async(task.id)
+    task.destroy
 
     respond_with(task)
   end
diff --git a/app/jobs/application_worker.rb b/app/jobs/application_worker.rb
new file mode 100644
index 0000000..2a35cdd
--- /dev/null
+++ b/app/jobs/application_worker.rb
@@ -0,0 +1,4 @@
+class ApplicationWorker
+  include Sidekiq::Worker
+  include Sidekiq::Throttled::Worker
+end
diff --git a/app/jobs/send_task_create_notification_worker.rb b/app/jobs/send_task_create_notification_worker.rb
new file mode 100644
index 0000000..628dd30
--- /dev/null
+++ b/app/jobs/send_task_create_notification_worker.rb
@@ -0,0 +1,11 @@
+class SendTaskCreateNotificationWorker < ApplicationWorker
+  sidekiq_options queue: :mailers
+  sidekiq_throttle_as :mailer
+
+  def perform(task_id)
+    task = Task.find_by(id: task_id)
+    return if task.blank?
+
+    UserMailer.with(user: task.author, task: task).task_created.deliver_now
+  end
+end
diff --git a/app/jobs/send_task_delete_notification_worker.rb b/app/jobs/send_task_delete_notification_worker.rb
new file mode 100644
index 0000000..06b64a0
--- /dev/null
+++ b/app/jobs/send_task_delete_notification_worker.rb
@@ -0,0 +1,11 @@
+class SendTaskDeleteNotificationWorker < ApplicationWorker
+  sidekiq_options queue: :mailers
+  sidekiq_throttle_as :mailer
+
+  def perform(task_id)
+    task = Task.find_by(id: task_id)
+    return if task.blank?
+
+    UserMailer.with(user: task.author, task: task).task_deleted.deliver_now
+  end
+end
diff --git a/app/jobs/send_task_update_notification_worker.rb b/app/jobs/send_task_update_notification_worker.rb
new file mode 100644
index 0000000..c135403
--- /dev/null
+++ b/app/jobs/send_task_update_notification_worker.rb
@@ -0,0 +1,12 @@
+class SendTaskUpdateNotificationWorker < ApplicationWorker
+  sidekiq_options queue: :mailers
+  sidekiq_options lock: :until_and_while_executing, on_conflict: { client: :log, server: :reject }
+  sidekiq_throttle_as :mailer
+
+  def perform(task_id)
+    task = Task.find_by(id: task_id)
+    return if task.blank?
+
+    UserMailer.with(user: task.author, task: task).task_updated.deliver_now
+  end
+end
diff --git a/config/application.rb b/config/application.rb
index 5ca8e76..7275102 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -12,6 +12,7 @@ class Application < Rails::Application
     config.load_defaults 6.0
 
     config.assets.paths << Rails.root.join('node_modules')
+    config.active_job.queue_adapter = :sidekiq
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration can go into files in config/initializers
     # -- all .rb files in that directory are automatically loaded after loading
diff --git a/config/initializers/sidekiq.rb b/config/initializers/sidekiq.rb
new file mode 100644
index 0000000..f872a3d
--- /dev/null
+++ b/config/initializers/sidekiq.rb
@@ -0,0 +1,29 @@
+require 'sidekiq/web'
+require 'sidekiq/throttled'
+require 'sidekiq/throttled/web'
+require 'sidekiq_unique_jobs/web'
+
+Sidekiq.configure_server do |config|
+  config.redis = { url: ENV['REDIS_URL'] }
+
+  config.client_middleware do |chain|
+    chain.add SidekiqUniqueJobs::Middleware::Client
+  end
+
+  config.server_middleware do |chain|
+    chain.add SidekiqUniqueJobs::Middleware::Server
+  end
+
+  SidekiqUniqueJobs::Server.configure(config)
+end
+
+Sidekiq.configure_client do |config|
+  config.redis = { url: ENV['REDIS_URL'] }
+
+  config.client_middleware do |chain|
+    chain.add SidekiqUniqueJobs::Middleware::Client
+  end
+end
+
+Sidekiq::Throttled.setup!
+Sidekiq::Throttled::Registry.add(:mailer, { threshold: { limit: 1, period: 5.seconds } })
diff --git a/config/routes.rb b/config/routes.rb
index 520db78..31c23ab 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,5 +1,6 @@
 Rails.application.routes.draw do
   mount LetterOpenerWeb::Engine, at: '/letter_opener' if Rails.env.development?
+  mount Sidekiq::Web => '/admin/sidekiq'
   root to: 'web/boards#show'
 
   scope module: :web do
diff --git a/config/sidekiq.yml b/config/sidekiq.yml
new file mode 100644
index 0000000..20aa386
--- /dev/null
+++ b/config/sidekiq.yml
@@ -0,0 +1,5 @@
+:concurrency: 5
+:verbose: true
+:queues:
+  - default
+  - mailers
diff --git a/docker-compose.yml b/docker-compose.yml
index 1992957..5b60413 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -15,6 +15,8 @@ services:
       - 3332:3332
     depends_on:
       - db
+      - redis
+      - sidekiq
     environment:
       &web-environment
       BUNDLE_PATH: /bundle_cache
@@ -32,6 +34,8 @@ services:
       MAILER_PORT: fake
       MAILER_DOMAIN: fake
       MAILER_AUTHENTICATION: fake
+
+      REDIS_URL: redis://redis
     command: bundle exec rails s -b '0.0.0.0' -p 3330
 
   db:
@@ -42,5 +46,15 @@ services:
       POSTGRES_USER: postgres
       POSTGRES_PASSWORD: postgres
 
+  redis:
+    image: redis:7.0.7-alpine
+
+  sidekiq:
+    build: .
+    command: bundle exec sidekiq -C /task_manager/config/sidekiq.yml
+    environment: *web-environment
+    volumes: *web-volumes
+    depends_on:
+      - redis
 volumes:
   bundle_cache:
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 0c03942..582205f 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -4,6 +4,8 @@
 ENV['RAILS_ENV'] ||= 'test'
 require_relative '../config/environment'
 require 'rails/test_help'
+require 'sidekiq/testing'
+Sidekiq::Testing.inline!
 
 class ActiveSupport::TestCase
   include ActionMailer::TestHelper