Include mailer header logo on custom images list

app/mailers/application_mailer.rb

@@ -1,5 +1,6 @@
 class ApplicationMailer < ActionMailer::Base
   helper :settings
+  helper :application
   default from: "#{Setting["mailer_from_name"]} <#{Setting["mailer_from_address"]}>"
   layout "mailer"
 end

app/models/site_customization/image.rb

@@ -5,7 +5,8 @@ class SiteCustomization::Image < ApplicationRecord
     "social_media_icon_twitter" => [246, 246],
     "apple-touch-icon-200" => [200, 200],
     "budget_execution_no_image" => [800, 600],
-    "map" => [420, 500]
+    "map" => [420, 500],
+    "logo_email" => [400, 80]
   }
 
   has_attached_file :image

app/views/layouts/_mailer_header.html.erb

@@ -5,7 +5,9 @@
         <tr>
           <td style="border-bottom: 1px solid #dadfe1; padding: 20px 0;">
             <a href="#" target="_blank">
-              <%= image_tag("logo_email.png",  style: "border: 0; display: block; width: 100%;max-width: 370px", alt: setting["org_name"]) %>
+              <%= image_tag(image_path_for("logo_email.png"),
+                            style: "border: 0;display: block;width: 100%;max-width: 400px",
+                            alt: setting["org_name"]) %>
             </a>
           </td>
         </tr>

spec/features/admin/site_customization/images_spec.rb

@@ -72,6 +72,23 @@ feature "Admin custom images" do
     end
   end
 
+  scenario "Image is replaced on admin newsletters" do
+    newsletter = create(:newsletter, segment_recipient: "all_users")
+
+    visit admin_site_customization_images_path
+
+    within("tr#image_logo_email") do
+      attach_file "site_customization_image_image", "spec/fixtures/files/logo_email_custom.png"
+      click_button "Update"
+    end
+
+    visit admin_newsletter_path(newsletter)
+
+    within(".newsletter-body-content") do
+      expect(page).to have_css("img[src*='logo_email_custom.png']")
+    end
+  end
+
   scenario "Upload invalid image" do
     visit admin_root_path