diff --git a/addons/mass_mailing/static/src/snippets/s_hr/000.scss b/addons/mass_mailing/static/src/snippets/s_hr/000.scss
index 3dadc70e714..ddea9a871f8 100644
--- a/addons/mass_mailing/static/src/snippets/s_hr/000.scss
+++ b/addons/mass_mailing/static/src/snippets/s_hr/000.scss
@@ -1,5 +1,5 @@
 
-.s_hr {
+.o_layout .s_hr {
     line-height: 0;
     hr {
         padding: 0;
diff --git a/addons/mass_mailing/views/snippets/s_hr.xml b/addons/mass_mailing/views/snippets/s_hr.xml
index 94f2a4f43ab..ab937496081 100644
--- a/addons/mass_mailing/views/snippets/s_hr.xml
+++ b/addons/mass_mailing/views/snippets/s_hr.xml
@@ -5,6 +5,9 @@
     <xpath expr="//div[hasclass('s_hr')]" position="attributes">
         <attribute name="class" add="o_mail_snippet_general pt16 pb16" remove="pt32 pb32" separator=" "/>
     </xpath>
+    <xpath expr="//hr" position="attributes">
+        <attribute name="class" remove="w-100 mx-auto" separator=" "/>
+    </xpath>
 </template>
 
 <template id="s_hr_options" inherit_id="mass_mailing.snippet_options">