Render custom mailer views if exists

app/views/admin/newsletters/show.html.erb

@@ -42,17 +42,17 @@
 </div>
 
 <div class="newsletter-body-content">
-  <%= render file: "app/views/layouts/_mailer_header.html.erb" %>
+  <%= render "layouts/mailer_header" %>
 
   <table cellpadding="0" cellspacing="0" border="0" style="background: #fff; margin: 0 auto; max-width: 700px; width:100%;">
     <tbody>
       <tr>
-        <%= render file: "app/views/mailer/newsletter.html.erb" %>
+        <%= render template: "mailer/newsletter" %>
       </tr>
     </tbody>
   </table>
 
-  <%= render file: "app/views/layouts/_mailer_footer.html.erb" %>
+  <%= render "layouts/mailer_footer" %>
 </div>
 
 <% if @newsletter.draft? && @newsletter.valid_segment_recipient? %>

app/views/admin/system_emails/view.html.erb

@@ -21,16 +21,16 @@
     <%= t("admin.newsletters.show.body_help_text") %>
   </p>
   <div class="newsletter-body-content">
-    <%= render file: "app/views/layouts/_mailer_header.html.erb" %>
+    <%= render "layouts/mailer_header" %>
 
     <table cellpadding="0" cellspacing="0" border="0" style="background: #fff; margin: 0 auto; max-width: 700px; width:100%;">
       <tbody>
         <tr>
-          <%= render file: "app/views/mailer/#{@system_email}.html.erb" %>
+          <%= render template: "mailer/#{@system_email}" %>
         </tr>
       </tbody>
     </table>
 
-    <%= render file: "app/views/layouts/_mailer_footer.html.erb" %>
+    <%= render "layouts/mailer_footer" %>
   </div>
 </div>