Return the missing mailer setup

config/environments/production.rb

@@ -70,6 +70,17 @@ Rails.application.configure do
     config.logger    = ActiveSupport::TaggedLogging.new(logger)
   end
 
+  config.action_mailer.smtp_settings = {
+    address:              ENV['OSEM_SMTP_ADDRESS'],
+    port:                 ENV['OSEM_SMTP_PORT'],
+    user_name:            ENV['OSEM_SMTP_USERNAME'],
+    password:             ENV['OSEM_SMTP_PASSWORD'],
+    authentication:       ENV['OSEM_SMTP_AUTHENTICATION'].try(:to_sym),
+    domain:               ENV['OSEM_SMTP_DOMAIN'],
+    enable_starttls_auto: ENV['OSEM_SMTP_ENABLE_STARTTLS_AUTO'],
+    openssl_verify_mode:  ENV['OSEM_SMTP_OPENSSL_VERIFY_MODE']
+  }.compact
+
   # Do not dump schema after migrations.
   config.active_record.dump_schema_after_migration = false
 end