diff --git a/addons/mass_mailing/static/src/scss/mass_mailing.ui.scss b/addons/mass_mailing/static/src/scss/mass_mailing.ui.scss
index f5e35ee09be..a280524dae5 100644
--- a/addons/mass_mailing/static/src/scss/mass_mailing.ui.scss
+++ b/addons/mass_mailing/static/src/scss/mass_mailing.ui.scss
@@ -347,5 +347,14 @@ body.editor_enable.o_basic_theme.o_in_iframe {
     }
     #oe_snippets.o_loaded {
         transform: translateX(0);
+
+        > .o_we_customize_panel .oe-toolbar {
+            #style.dropup, #font-size.dropup {
+                > .dropdown-menu {
+                    overflow-y: scroll;
+                    max-height: 200px;
+                }
+            }
+        }
     }
 }