Use letter_opener for dev environment

config/environments/development.rb

@@ -38,6 +38,10 @@ Rails.application.configure do
   config.active_storage.service = :local
 
   # Don't care if the mailer can't send.
+  config.action_mailer.perform_deliveries = true
+
+  # Perform deliveries via letter opener
+  config.action_mailer.delivery_method = :letter_opener
   config.action_mailer.raise_delivery_errors = false
 
   config.action_mailer.perform_caching = false