diff --git a/railties/test/generators/action_mailbox_install_generator_test.rb b/railties/test/generators/action_mailbox_install_generator_test.rb
new file mode 100644
index 0000000000..1822b04d45
--- /dev/null
+++ b/railties/test/generators/action_mailbox_install_generator_test.rb
@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require "generators/generators_test_helper"
+require "generators/action_mailbox/install/install_generator"
+
+class ActionMailbox::Generators::InstallGeneratorTest < Rails::Generators::TestCase
+  include GeneratorsTestHelper
+
+  def setup
+    Rails.application = TestApp::Application
+    Rails.application.config.root = Pathname(destination_root)
+
+    production_env_config = Pathname("config/environments/production.rb").expand_path(destination_root)
+    production_env_config.dirname.mkpath
+    production_env_config.write <<~PRODUCTION
+      Rails.application.configure do
+      end
+    PRODUCTION
+  end
+
+  def teardown
+    Rails.application = Rails.application.instance
+  end
+
+  def test_create_action_mailbox_files
+    with_database_configuration { run_generator }
+
+    assert_file "app/mailboxes/application_mailbox.rb"
+  end
+
+  def test_add_action_mailbox_production_environment_config
+    with_database_configuration { run_generator }
+
+    assert_file "config/environments/production.rb" do |content|
+      assert_match("Prepare the ingress controller used to receive mail", content)
+      assert_match("config.action_mailbox.ingress = :relay", content)
+    end
+  end
+
+  def test_create_migrations
+    with_database_configuration { run_generator }
+
+    assert_migration "db/migrate/create_active_storage_tables.active_storage.rb"
+    assert_migration "db/migrate/create_action_mailbox_tables.action_mailbox.rb"
+  end
+end