Remove ActionMailer

This application does not send any mail, so we don't need to be
including or configuring `ActionMailer`.

config/application.rb

@@ -7,7 +7,7 @@
 # require "active_record/railtie"
 # require "active_storage/engine"
 require "action_controller/railtie"
-require "action_mailer/railtie"
+# require "action_mailer/railtie"
 # require "action_mailbox/engine"
 # require "action_text/engine"
 require "action_view/railtie"

config/environments/development.rb

@@ -31,15 +31,6 @@
     config.cache_store = :null_store
   end
 
-  # Don't care if the mailer can't send.
-  config.action_mailer.raise_delivery_errors = false
-
-  # Disable caching for Action Mailer templates even if Action Controller
-  # caching is enabled.
-  config.action_mailer.perform_caching = false
-
-  config.action_mailer.default_url_options = { host: "localhost", port: 3000 }
-
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 

config/environments/production.rb

@@ -60,14 +60,6 @@
   # config.active_job.queue_adapter = :resque
   # config.active_job.queue_name_prefix = "hmrc_manuals_api_production"
 
-  # Disable caching for Action Mailer templates even if Action Controller
-  # caching is enabled.
-  config.action_mailer.perform_caching = false
-
-  # Ignore bad email addresses and do not raise email delivery errors.
-  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
-  # config.action_mailer.raise_delivery_errors = false
-
   # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
   # the I18n.default_locale when a translation cannot be found).
   config.i18n.fallbacks = true

config/environments/test.rb

@@ -32,19 +32,6 @@
   # Disable request forgery protection in test environment.
   config.action_controller.allow_forgery_protection = false
 
-  # Disable caching for Action Mailer templates even if Action Controller
-  # caching is enabled.
-  config.action_mailer.perform_caching = false
-
-  # Tell Action Mailer not to deliver emails to the real world.
-  # The :test delivery method accumulates sent emails in the
-  # ActionMailer::Base.deliveries array.
-  config.action_mailer.delivery_method = :test
-
-  # Unlike controllers, the mailer instance doesn't have any context about the
-  # incoming request so you'll need to provide the :host parameter yourself.
-  # config.action_mailer.default_url_options = { host: "www.example.com" }
-
   # Print deprecation notices to the stderr.
   config.active_support.deprecation = :stderr