diff --git a/README.md b/README.md
index 27c2fabd..f1efb824 100644
--- a/README.md
+++ b/README.md
@@ -765,7 +765,8 @@ Default: `[see next line]`
           \ 'unite' : 1,
           \ 'text' : 1,
           \ 'vimwiki' : 1,
-          \ 'pandoc' : 1
+          \ 'pandoc' : 1,
+          \ 'mail' : 1
           \}
 
 ### The `g:ycm_filetype_specific_completion_to_disable` option
diff --git a/python/ycm/server/default_settings.json b/python/ycm/server/default_settings.json
index bb3aae7b..83f68aa3 100644
--- a/python/ycm/server/default_settings.json
+++ b/python/ycm/server/default_settings.json
@@ -27,7 +27,8 @@
     "unite": 1,
     "text": 1,
     "vimwiki": 1,
-    "pandoc": 1
+    "pandoc": 1,
+    "mail": 1
   },
   "auto_start_csharp_server": 1,
   "auto_stop_csharp_server": 1,