diff --git a/addons/mail/static/src/components/discuss_sidebar_mailbox/discuss_sidebar_mailbox.xml b/addons/mail/static/src/components/discuss_sidebar_mailbox/discuss_sidebar_mailbox.xml
index fe59800a10f..4b995610bd2 100644
--- a/addons/mail/static/src/components/discuss_sidebar_mailbox/discuss_sidebar_mailbox.xml
+++ b/addons/mail/static/src/components/discuss_sidebar_mailbox/discuss_sidebar_mailbox.xml
@@ -1,23 +1,25 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <templates xml:space="preserve">
     <t t-name="mail.DiscussSidebarMailbox" owl="1">
-        <div class="o_DiscussSidebarMailbox"
-            t-att-class="{
-                'o-active': mailbox and mailbox === messaging.discuss.thread,
-                'o-starred-box': mailbox and mailbox === messaging.starred,
-            }" t-attf-class="{{ className }}" t-on-click="mailbox.onClick" t-att-data-thread-local-id="mailbox.localId" t-att-data-thread-name="mailbox.displayName"
-            t-ref="root"
-        >
-            <ThreadIcon className="'o_DiscussSidebarMailbox_item'" threadLocalId="mailbox.localId"/>
-            <div class="o_DiscussSidebarMailbox_item o_DiscussSidebarMailbox_name">
-                <t t-esc="mailbox.displayName"/>
-            </div>
-            <div class="o-autogrow o_DiscussSidebarMailbox_item"/>
-            <t t-if="mailbox.counter > 0">
-                <div class="o_DiscussSidebarMailbox_counter o_DiscussSidebarMailbox_item badge badge-pill">
-                    <t t-esc="mailbox.counter"/>
+        <t t-if="mailbox">
+            <div class="o_DiscussSidebarMailbox"
+                t-att-class="{
+                    'o-active': mailbox === messaging.discuss.thread,
+                    'o-starred-box': mailbox === messaging.starred,
+                }" t-attf-class="{{ className }}" t-on-click="mailbox.onClick" t-att-data-thread-local-id="mailbox.localId" t-att-data-thread-name="mailbox.displayName"
+                t-ref="root"
+            >
+                <ThreadIcon className="'o_DiscussSidebarMailbox_item'" threadLocalId="mailbox.localId"/>
+                <div class="o_DiscussSidebarMailbox_item o_DiscussSidebarMailbox_name">
+                    <t t-esc="mailbox.displayName"/>
                 </div>
-            </t>
-        </div>
+                <div class="o-autogrow o_DiscussSidebarMailbox_item"/>
+                <t t-if="mailbox.counter > 0">
+                    <div class="o_DiscussSidebarMailbox_counter o_DiscussSidebarMailbox_item badge badge-pill">
+                        <t t-esc="mailbox.counter"/>
+                    </div>
+                </t>
+            </div>
+        </t>
     </t>
 </templates>