Add mail_methods controller from spree_backend related to config

app/controllers/spree/admin/mail_methods_controller.rb

@@ -0,0 +1,38 @@
+module Spree
+  module Admin
+    class MailMethodsController < Spree::Admin::BaseController
+      after_filter :initialize_mail_settings
+
+      def update
+        if params[:smtp_password].blank?
+          params.delete(:smtp_password)
+        end
+
+        params.each do |name, value|
+          next unless Spree::Config.has_preference? name
+          Spree::Config[name] = value
+        end
+
+        flash[:success] = Spree.t(:successfully_updated, :resource => Spree.t(:mail_methods))
+        render :edit
+      end
+
+      def testmail
+        if TestMailer.test_email(try_spree_current_user).deliver
+          flash[:success] = Spree.t('admin.mail_methods.testmail.delivery_success')
+        else
+          flash[:error] = Spree.t('admin.mail_methods.testmail.delivery_error')
+        end
+      rescue Exception => e
+        flash[:error] = Spree.t('admin.mail_methods.testmail.error') % {:e => e}
+      ensure
+        redirect_to edit_admin_mail_method_url
+      end
+
+      private
+        def initialize_mail_settings
+          Spree::Core::MailSettings.init
+        end
+    end
+  end
+end