diff --git a/app/assets/stylesheets/admin.scss b/app/assets/stylesheets/admin.scss
index 8719d767e..7b0ee0300 100644
--- a/app/assets/stylesheets/admin.scss
+++ b/app/assets/stylesheets/admin.scss
@@ -40,6 +40,13 @@ body {
     }
   }
 }
+.editormd .CodeMirror{
+  margin-top: 35px!important;
+}
+
+.CodeMirror-gutter .CodeMirror-linenumbers {
+  width: 28px!important;
+}
 
 input.form-control {
   font-size: 14px;
diff --git a/app/views/admins/feedbacks/_history_form_modal.html.erb b/app/views/admins/feedbacks/_history_form_modal.html.erb
index df12a73d3..c5304bfc4 100644
--- a/app/views/admins/feedbacks/_history_form_modal.html.erb
+++ b/app/views/admins/feedbacks/_history_form_modal.html.erb
@@ -2,7 +2,12 @@
   <div class="modal-dialog modal-dialog-centered" role="document" style="max-width: 800px">
     <div class="modal-content">
       <div class="modal-header">
-        <h5 class="modal-title">发送邮件给<%= @feedback&.user&.mail%></h5>
+        <h5 class="modal-title">
+          发送邮件给<%= @feedback&.user&.mail%>
+          <% if @feedback&.user&.mail.end_with?('@example.org') || @feedback&.user&.mail.end_with?('@gitlink.org.cn')%>
+            <span style="color: red">(该邮箱不可用)</span>
+          <% end %>
+        </h5>
         <button type="button" class="close" data-dismiss="modal" aria-label="Close">
           <span aria-hidden="true">&times;</span>
         </button>