Display mailer previews in sandbox

config/environments/sandbox.rb

@@ -1,7 +1,7 @@
-require "active_support/core_ext/integer/time"
+require 'active_support/core_ext/integer/time'
 
 Rails.application.configure do
-  config.host = ENV.fetch("HOST", "localhost:3000")
+  config.host = ENV.fetch('HOST', 'localhost:3000')
 
   # Settings specified here will take precedence over those in config/application.rb.
 
@@ -53,19 +53,19 @@
   # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
   config.force_ssl = true
 
-  if ENV["RAILS_LOG_TO_STDOUT"].present?
+  if ENV['RAILS_LOG_TO_STDOUT'].present?
     config.logger = ActiveSupport::Logger.new(STDOUT)
-      .tap  { |logger| logger.formatter = ::Logger::Formatter.new }
+      .tap  { |logger| logger.formatter = Logger::Formatter.new }
       .then { |logger| ActiveSupport::TaggedLogging.new(logger) }
   end
 
   # Prepend all log lines with the following tags.
-  config.log_tags = [ :request_id ]
+  config.log_tags = [:request_id]
 
   # Info include generic and useful information about system operation, but avoids logging too much
   # information to avoid inadvertent exposure of personally identifiable information (PII). If you
   # want to log everything, set the level to "debug".
-  config.log_level = ENV.fetch("RAILS_LOG_LEVEL", "info")
+  config.log_level = ENV.fetch('RAILS_LOG_LEVEL', 'info')
 
   # Use a different cache store in production.
   # config.cache_store = :mem_cache_store
@@ -74,6 +74,7 @@
   config.active_job.queue_adapter = :good_job
   # config.active_job.queue_name_prefix = "data_pass_production"
 
+  config.action_mailer.show_previews = true
   config.action_mailer.delivery_method = :mailjet
   config.action_mailer.perform_caching = false